21106775252 has 24 divisors (see below), whose sum is σ = 38952846240. Its totient is φ = 9979446240.

The previous prime is 21106775243. The next prime is 21106775269. The reversal of 21106775252 is 25257760112.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215558 + ... + 297789.

It is an arithmetic number, because the mean of its divisors is an integer number (1623035260).

Almost surely, 2^21106775252 is an apocalyptic number.

It is an amenable number.

21106775252 is a deficient number, since it is larger than the sum of its proper divisors (17846070988).

21106775252 is a wasteful number, since it uses less digits than its factorization.

21106775252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513911 (or 513909 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 38.

The spelling of 21106775252 in words is "twenty-one billion, one hundred six million, seven hundred seventy-five thousand, two hundred fifty-two".