15625440 has 96 divisors (see below), whose sum is σ = 54704160. Its totient is φ = 4165632.

The previous prime is 15625427. The next prime is 15625451. The reversal of 15625440 is 4452651.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 15 ways as a sum of consecutive naturals, for example, 2512 + ... + 6128.

It is an arithmetic number, because the mean of its divisors is an integer number (569835).

Almost surely, 2^15625440 is an apocalyptic number.

15625440 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 15625440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27352080).

15625440 is an abundant number, since it is smaller than the sum of its proper divisors (39078720).

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

15625440 is a wasteful number, since it uses less digits than its factorization.

15625440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641 (or 3627 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 15625440 is about 3952.9027309055. The cubic root of 15625440 is about 250.0023466446.

The spelling of 15625440 in words is "fifteen million, six hundred twenty-five thousand, four hundred forty".