21706419906 has 32 divisors (see below), whose sum is σ = 48291222720. Its totient is φ = 7227263232.

The previous prime is 21706419899. The next prime is 21706419919. The reversal of 21706419906 is 60991460712.

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, 179935 + ... + 275298.

It is an arithmetic number, because the mean of its divisors is an integer number (1509100710).

Almost surely, 2^21706419906 is an apocalyptic number.

21706419906 is an abundant number, since it is smaller than the sum of its proper divisors (26584802814).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21706419906 is a wasteful number, since it uses less digits than its factorization.

21706419906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456127 (or 456121 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 21706419906 in words is "twenty-one billion, seven hundred six million, four hundred nineteen thousand, nine hundred six".