15700991391 has 12 divisors (see below), whose sum is σ = 22796721168. Its totient is φ = 10413091584.

The previous prime is 15700991389. The next prime is 15700991399. The reversal of 15700991391 is 19319900751.

It is a happy number.

It is not a de Polignac number, because 15700991391 - 2¹ = 15700991389 is a prime.

It is a super-2 number, since 2×15700991391² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15700991399) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4517835 + ... + 4521308.

It is an arithmetic number, because the mean of its divisors is an integer number (1899726764).

Almost surely, 2^15700991391 is an apocalyptic number.

15700991391 is a deficient number, since it is larger than the sum of its proper divisors (7095729777).

15700991391 is a wasteful number, since it uses less digits than its factorization.

15700991391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9039342 (or 9039339 counting only the distinct ones).

The product of its (nonzero) digits is 76545, while the sum is 45.

The spelling of 15700991391 in words is "fifteen billion, seven hundred million, nine hundred ninety-one thousand, three hundred ninety-one".