21652951525909 has 4 divisors (see below), whose sum is σ = 23621401664640. Its totient is φ = 19684501387180.

The previous prime is 21652951525903. The next prime is 21652951525913. The reversal of 21652951525909 is 90952515925612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21652951525909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21652951525903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 984225069349 + ... + 984225069370.

It is an arithmetic number, because the mean of its divisors is an integer number (5905350416160).

Almost surely, 2^{21652951525909} is an apocalyptic number.

It is an amenable number.

21652951525909 is a deficient number, since it is larger than the sum of its proper divisors (1968450138731).

21652951525909 is a wasteful number, since it uses less digits than its factorization.

21652951525909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1968450138730.

The product of its (nonzero) digits is 21870000, while the sum is 61.

The spelling of 21652951525909 in words is "twenty-one trillion, six hundred fifty-two billion, nine hundred fifty-one million, five hundred twenty-five thousand, nine hundred nine".