20921586889072 has 40 divisors (see below), whose sum is σ = 42360778665216. Its totient is φ = 10000125137856.

The previous prime is 20921586889061. The next prime is 20921586889079. The reversal of 20921586889072 is 27098868512902.

It is a junction number, because it is equal to n+sod(n) for n = 20921586888989 and 20921586889007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20921586889079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323470678 + ... + 323535349.

Almost surely, 2^{20921586889072} is an apocalyptic number.

It is an amenable number.

20921586889072 is an abundant number, since it is smaller than the sum of its proper divisors (21439191776144).

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

20921586889072 is a wasteful number, since it uses less digits than its factorization.

20921586889072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647006125 (or 647006119 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 67.

The spelling of 20921586889072 in words is "twenty trillion, nine hundred twenty-one billion, five hundred eighty-six million, eight hundred eighty-nine thousand, seventy-two".