1553121520 has 20 divisors (see below), whose sum is σ = 3611007720. Its totient is φ = 621248576.

The previous prime is 1553121499. The next prime is 1553121571. The reversal of 1553121520 is 251213551.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×1553121520² = 4824372911774220800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9706930 + ... + 9707089.

It is an arithmetic number, because the mean of its divisors is an integer number (180550386).

Almost surely, 2^1553121520 is an apocalyptic number.

1553121520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1553121520 is an abundant number, since it is smaller than the sum of its proper divisors (2057886200).

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

1553121520 is a wasteful number, since it uses less digits than its factorization.

1553121520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19414032 (or 19414026 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 1553121520 is about 39409.6627745024. The cubic root of 1553121520 is about 1158.0708919207.

The spelling of 1553121520 in words is "one billion, five hundred fifty-three million, one hundred twenty-one thousand, five hundred twenty".