21751545051 has 12 divisors (see below), whose sum is σ = 31435661712. Its totient is φ = 14493293136.

The previous prime is 21751545043. The next prime is 21751545071. The reversal of 21751545051 is 15054515712.

21751545051 is a `hidden beast` number, since 2 + 17 + 51 + 545 + 0 + 51 = 666.

It is not a de Polignac number, because 21751545051 - 2³ = 21751545043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21751544997 and 21751545015.

It is not an unprimeable number, because it can be changed into a prime (21751545071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 626911 + ... + 660696.

It is an arithmetic number, because the mean of its divisors is an integer number (2619638476).

Almost surely, 2^21751545051 is an apocalyptic number.

21751545051 is a deficient number, since it is larger than the sum of its proper divisors (9684116661).

21751545051 is a wasteful number, since it uses less digits than its factorization.

21751545051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289490 (or 1289487 counting only the distinct ones).

The product of its (nonzero) digits is 35000, while the sum is 36.

The spelling of 21751545051 in words is "twenty-one billion, seven hundred fifty-one million, five hundred forty-five thousand, fifty-one".