21492310820 has 24 divisors (see below), whose sum is σ = 45300409728. Its totient is φ = 8565199200.

The previous prime is 21492310817. The next prime is 21492310837. The reversal of 21492310820 is 2801329412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1977266 + ... + 1988105.

It is an arithmetic number, because the mean of its divisors is an integer number (1887517072).

Almost surely, 2^21492310820 is an apocalyptic number.

21492310820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21492310820 is an abundant number, since it is smaller than the sum of its proper divisors (23808098908).

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

21492310820 is a wasteful number, since it uses less digits than its factorization.

21492310820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3965651 (or 3965649 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The spelling of 21492310820 in words is "twenty-one billion, four hundred ninety-two million, three hundred ten thousand, eight hundred twenty".