15900691122649 has 4 divisors (see below), whose sum is σ = 15901959031780. Its totient is φ = 15899423213520.

The previous prime is 15900691122643. The next prime is 15900691122661. The reversal of 15900691122649 is 94622119600951.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7345417119049 + 8555274003600 = 2710243^2 + 2924940^2 .

It is a cyclic number.

It is not a de Polignac number, because 15900691122649 - 2³³ = 15892101188057 is a prime.

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 15900691122649.

It is not an unprimeable number, because it can be changed into a prime (15900691122643) 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, 633935754 + ... + 633960835.

It is an arithmetic number, because the mean of its divisors is an integer number (3975489757945).

Almost surely, 2^{15900691122649} is an apocalyptic number.

It is an amenable number.

15900691122649 is a deficient number, since it is larger than the sum of its proper divisors (1267909131).

15900691122649 is a wasteful number, since it uses less digits than its factorization.

15900691122649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1267909130.

The product of its (nonzero) digits is 2099520, while the sum is 55.

The spelling of 15900691122649 in words is "fifteen trillion, nine hundred billion, six hundred ninety-one million, one hundred twenty-two thousand, six hundred forty-nine".