21701921420 has 24 divisors (see below), whose sum is σ = 45641781024. Its totient is φ = 8667864576.

The previous prime is 21701921413. The next prime is 21701921459. The reversal of 21701921420 is 2412910712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 792704 + ... + 819623.

It is an arithmetic number, because the mean of its divisors is an integer number (1901740876).

Almost surely, 2^21701921420 is an apocalyptic number.

21701921420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21701921420 is an abundant number, since it is smaller than the sum of its proper divisors (23939859604).

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

21701921420 is a wasteful number, since it uses less digits than its factorization.

21701921420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1613009 (or 1613007 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The spelling of 21701921420 in words is "twenty-one billion, seven hundred one million, nine hundred twenty-one thousand, four hundred twenty".