20421531564234 has 32 divisors (see below), whose sum is σ = 43297888568256. Its totient is φ = 6399007991040.

The previous prime is 20421531564209. The next prime is 20421531564253. The reversal of 20421531564234 is 43246513512402.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120962257 + ... + 121130964.

It is an arithmetic number, because the mean of its divisors is an integer number (1353059017758).

Almost surely, 2^{20421531564234} is an apocalyptic number.

20421531564234 is an abundant number, since it is smaller than the sum of its proper divisors (22876357004022).

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

20421531564234 is a wasteful number, since it uses less digits than its factorization.

20421531564234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242094070.

The product of its (nonzero) digits is 691200, while the sum is 42.

The spelling of 20421531564234 in words is "twenty trillion, four hundred twenty-one billion, five hundred thirty-one million, five hundred sixty-four thousand, two hundred thirty-four".