15625718640 has 1280 divisors, whose sum is σ = 70349783040. Its totient is φ = 3105423360.

The previous prime is 15625718639. The next prime is 15625718659. The reversal of 15625718640 is 4681752651.

15625718640 is a `hidden beast` number, since 1 + 5 + 625 + 7 + 18 + 6 + 4 + 0 = 666.

It is a super-4 number, since 4×15625718640⁴ (a number of 42 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 294824854 + ... + 294824906.

It is an arithmetic number, because the mean of its divisors is an integer number (54960768).

Almost surely, 2^15625718640 is an apocalyptic number.

15625718640 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 15625718640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35174891520).

15625718640 is an abundant number, since it is smaller than the sum of its proper divisors (54724064400).

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

15625718640 is a wasteful number, since it uses less digits than its factorization.

15625718640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 15625718640 in words is "fifteen billion, six hundred twenty-five million, seven hundred eighteen thousand, six hundred forty".