21158562020 has 24 divisors (see below), whose sum is σ = 44534212800. Its totient is φ = 8444142432.

The previous prime is 21158561987. The next prime is 21158562031. The reversal of 21158562020 is 2026585112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1196150 + ... + 1213709.

It is an arithmetic number, because the mean of its divisors is an integer number (1855592200).

Almost surely, 2^21158562020 is an apocalyptic number.

21158562020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21158562020 is an abundant number, since it is smaller than the sum of its proper divisors (23375650780).

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

21158562020 is a wasteful number, since it uses less digits than its factorization.

21158562020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2410307 (or 2410305 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The spelling of 21158562020 in words is "twenty-one billion, one hundred fifty-eight million, five hundred sixty-two thousand, twenty".