1225991520 has 288 divisors, whose sum is σ = 4568054400. Its totient is φ = 297603072.

The previous prime is 1225991513. The next prime is 1225991531. The reversal of 1225991520 is 251995221.

It is a happy number.

1225991520 is a `hidden beast` number, since 12 + 2 + 599 + 1 + 52 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×1225991520² = 3006110414223820800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1478466 + ... + 1479294.

It is an arithmetic number, because the mean of its divisors is an integer number (15861300).

Almost surely, 2^1225991520 is an apocalyptic number.

1225991520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1225991520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2284027200).

1225991520 is an abundant number, since it is smaller than the sum of its proper divisors (3342062880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1225991520 is a wasteful number, since it uses less digits than its factorization.

1225991520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942 (or 931 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 1225991520 is about 35014.1617063725. The cubic root of 1225991520 is about 1070.2760867907.

The spelling of 1225991520 in words is "one billion, two hundred twenty-five million, nine hundred ninety-one thousand, five hundred twenty".