15660617331 has 4 divisors (see below), whose sum is σ = 20880823112. Its totient is φ = 10440411552.

The previous prime is 15660617327. The next prime is 15660617333. The reversal of 15660617331 is 13371606651.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 15660617331 - 2² = 15660617327 is a prime.

It is a super-2 number, since 2×15660617331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15660617331.

It is not an unprimeable number, because it can be changed into a prime (15660617333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2610102886 + ... + 2610102891.

It is an arithmetic number, because the mean of its divisors is an integer number (5220205778).

Almost surely, 2^15660617331 is an apocalyptic number.

15660617331 is a deficient number, since it is larger than the sum of its proper divisors (5220205781).

15660617331 is an equidigital number, since it uses as much as digits as its factorization.

15660617331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5220205780.

The product of its (nonzero) digits is 68040, while the sum is 39.

The spelling of 15660617331 in words is "fifteen billion, six hundred sixty million, six hundred seventeen thousand, three hundred thirty-one".