21006259708 has 12 divisors (see below), whose sum is σ = 42012519472. Its totient is φ = 9002682720.

The previous prime is 21006259607. The next prime is 21006259709. The reversal of 21006259708 is 80795260012.

21006259708 is an admirable number.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21006259709) 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, 375111753 + ... + 375111808.

Almost surely, 2^21006259708 is an apocalyptic number.

21006259708 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21006259708 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21006259708 is a wasteful number, since it uses less digits than its factorization.

21006259708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750223572 (or 750223570 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 21006259708 in words is "twenty-one billion, six million, two hundred fifty-nine thousand, seven hundred eight".