21775512137 has 12 divisors (see below), whose sum is σ = 22430777904. Its totient is φ = 21138327000.

The previous prime is 21775512103. The next prime is 21775512139. The reversal of 21775512137 is 73121557712.

It is not a de Polignac number, because 21775512137 - 2⁸ = 21775511881 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21775512094 and 21775512103.

It is not an unprimeable number, because it can be changed into a prime (21775512139) 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, 265262 + ... + 337512.

It is an arithmetic number, because the mean of its divisors is an integer number (1869231492).

Almost surely, 2^21775512137 is an apocalyptic number.

It is an amenable number.

21775512137 is a deficient number, since it is larger than the sum of its proper divisors (655265767).

21775512137 is an equidigital number, since it uses as much as digits as its factorization.

21775512137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72500 (or 72457 counting only the distinct ones).

The product of its digits is 102900, while the sum is 41.

The spelling of 21775512137 in words is "twenty-one billion, seven hundred seventy-five million, five hundred twelve thousand, one hundred thirty-seven".