15499771923 has 6 divisors (see below), whose sum is σ = 20666650084. Its totient is φ = 10333037524.

The previous prime is 15499771883. The next prime is 15499771927. The reversal of 15499771923 is 32917799451.

It is a happy number.

It is not a de Polignac number, because 15499771923 - 2²⁰ = 15498723347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15499771927) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 179698 + ... + 251576.

Almost surely, 2^15499771923 is an apocalyptic number.

15499771923 is a deficient number, since it is larger than the sum of its proper divisors (5166878161).

15499771923 is an frugal number, since it uses more digits than its factorization.

15499771923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143761 (or 71882 counting only the distinct ones).

The product of its digits is 4286520, while the sum is 57.

The spelling of 15499771923 in words is "fifteen billion, four hundred ninety-nine million, seven hundred seventy-one thousand, nine hundred twenty-three".