15557291640 has 384 divisors, whose sum is σ = 56838862080. Its totient is φ = 3657830400.

The previous prime is 15557291639. The next prime is 15557291671. The reversal of 15557291640 is 4619275551.

It is a happy number.

15557291640 is a `hidden beast` number, since 1 + 5 + 557 + 2 + 91 + 6 + 4 + 0 = 666.

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 95 ways as a sum of consecutive naturals, for example, 35928864 + ... + 35929296.

It is an arithmetic number, because the mean of its divisors is an integer number (148017870).

Almost surely, 2^15557291640 is an apocalyptic number.

15557291640 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 15557291640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28419431040).

15557291640 is an abundant number, since it is smaller than the sum of its proper divisors (41281570440).

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

15557291640 is a wasteful number, since it uses less digits than its factorization.

15557291640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 708 counting only the distinct ones).

The product of its (nonzero) digits is 378000, while the sum is 45.

The spelling of 15557291640 in words is "fifteen billion, five hundred fifty-seven million, two hundred ninety-one thousand, six hundred forty".