21661030434020 has 24 divisors (see below), whose sum is σ = 45489705504768. Its totient is φ = 8664118536800.

The previous prime is 21661030434007. The next prime is 21661030434083. The reversal of 21661030434020 is 2043403016612.

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, 17746916 + ... + 18928155.

It is an arithmetic number, because the mean of its divisors is an integer number (1895404396032).

Almost surely, 2^{21661030434020} is an apocalyptic number.

21661030434020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21661030434020 is an abundant number, since it is smaller than the sum of its proper divisors (23828675070748).

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

21661030434020 is a wasteful number, since it uses less digits than its factorization.

21661030434020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36704611 (or 36704609 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The spelling of 21661030434020 in words is "twenty-one trillion, six hundred sixty-one billion, thirty million, four hundred thirty-four thousand, twenty".