1225691478 has 96 divisors (see below), whose sum is σ = 2961653760. Its totient is φ = 363242880.

The previous prime is 1225691477. The next prime is 1225691497. The reversal of 1225691478 is 8741965221.

1225691478 is a `hidden beast` number, since 1 + 2 + 2 + 569 + 14 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225691471) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 1986226 + ... + 1986842.

It is an arithmetic number, because the mean of its divisors is an integer number (30850560).

Almost surely, 2^1225691478 is an apocalyptic number.

1225691478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1225691478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1480826880).

1225691478 is an abundant number, since it is smaller than the sum of its proper divisors (1735962282).

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

1225691478 is a wasteful number, since it uses less digits than its factorization.

1225691478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 839 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 1225691478 is about 35009.8768635367. The cubic root of 1225691478 is about 1070.1887686288.

The spelling of 1225691478 in words is "one billion, two hundred twenty-five million, six hundred ninety-one thousand, four hundred seventy-eight".