21670909895 has 16 divisors (see below), whose sum is σ = 28317708000. Its totient is φ = 15857912448.

The previous prime is 21670909877. The next prime is 21670909921. The reversal of 21670909895 is 59890907612.

It is a cyclic number.

It is not a de Polignac number, because 21670909895 - 2⁶ = 21670909831 is a prime.

It is a super-2 number, since 2×21670909895² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21670909895.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3930260 + ... + 3935769.

It is an arithmetic number, because the mean of its divisors is an integer number (1769856750).

Almost surely, 2^21670909895 is an apocalyptic number.

21670909895 is a deficient number, since it is larger than the sum of its proper divisors (6646798105).

21670909895 is a wasteful number, since it uses less digits than its factorization.

21670909895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7866082.

The product of its (nonzero) digits is 2449440, while the sum is 56.

The spelling of 21670909895 in words is "twenty-one billion, six hundred seventy million, nine hundred nine thousand, eight hundred ninety-five".