21756272851 has 8 divisors (see below), whose sum is σ = 21831427584. Its totient is φ = 21681175560.

The previous prime is 21756272849. The next prime is 21756272893. The reversal of 21756272851 is 15827265712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21756272851 - 2¹ = 21756272849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21756272821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 828810 + ... + 854656.

It is an arithmetic number, because the mean of its divisors is an integer number (2728928448).

Almost surely, 2^21756272851 is an apocalyptic number.

21756272851 is a deficient number, since it is larger than the sum of its proper divisors (75154733).

21756272851 is a wasteful number, since it uses less digits than its factorization.

21756272851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28721.

The product of its digits is 470400, while the sum is 46.

The spelling of 21756272851 in words is "twenty-one billion, seven hundred fifty-six million, two hundred seventy-two thousand, eight hundred fifty-one".