21771382275 has 36 divisors (see below), whose sum is σ = 41047339320. Its totient is φ = 11000275200.

The previous prime is 21771382247. The next prime is 21771382319. The reversal of 21771382275 is 57228317712.

It is not a de Polignac number, because 21771382275 - 2²⁸ = 21502946819 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21771382275.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2542086 + ... + 2550635.

It is an arithmetic number, because the mean of its divisors is an integer number (1140203870).

Almost surely, 2^21771382275 is an apocalyptic number.

21771382275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21771382275 is a deficient number, since it is larger than the sum of its proper divisors (19275957045).

21771382275 is a wasteful number, since it uses less digits than its factorization.

21771382275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5092756 (or 5092748 counting only the distinct ones).

The product of its digits is 329280, while the sum is 45.

Adding to 21771382275 its reverse (57228317712), we get a palindrome (78999699987).

The spelling of 21771382275 in words is "twenty-one billion, seven hundred seventy-one million, three hundred eighty-two thousand, two hundred seventy-five".