21650517051 has 8 divisors (see below), whose sum is σ = 28872021264. Its totient is φ = 14431345440.

The previous prime is 21650517017. The next prime is 21650517089. The reversal of 21650517051 is 15071505612.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21650517051 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21650517001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 561376 + ... + 598701.

It is an arithmetic number, because the mean of its divisors is an integer number (3609002658).

Almost surely, 2^21650517051 is an apocalyptic number.

21650517051 is a deficient number, since it is larger than the sum of its proper divisors (7221504213).

21650517051 is a wasteful number, since it uses less digits than its factorization.

21650517051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1166301.

The product of its (nonzero) digits is 10500, while the sum is 33.

The spelling of 21650517051 in words is "twenty-one billion, six hundred fifty million, five hundred seventeen thousand, fifty-one".