15591502081 has 4 divisors (see below), whose sum is σ = 15687155632. Its totient is φ = 15495848532.

The previous prime is 15591502079. The next prime is 15591502093. The reversal of 15591502081 is 18020519551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 15591502081 - 2¹ = 15591502079 is a prime.

It is a super-2 number, since 2×15591502081² (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 15591502081.

It is not an unprimeable number, because it can be changed into a prime (15591502001) 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, 47826531 + ... + 47826856.

It is an arithmetic number, because the mean of its divisors is an integer number (3921788908).

Almost surely, 2^15591502081 is an apocalyptic number.

It is an amenable number.

15591502081 is a deficient number, since it is larger than the sum of its proper divisors (95653551).

15591502081 is an equidigital number, since it uses as much as digits as its factorization.

15591502081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95653550.

The product of its (nonzero) digits is 18000, while the sum is 37.

The spelling of 15591502081 in words is "fifteen billion, five hundred ninety-one million, five hundred two thousand, eighty-one".