21020566770 has 384 divisors, whose sum is σ = 68635607040. Its totient is φ = 4526565120.

The previous prime is 21020566711. The next prime is 21020566789. The reversal of 21020566770 is 7766502012.

21020566770 is a `hidden beast` number, since 2 + 1 + 0 + 20 + 566 + 7 + 70 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 21210975 + ... + 21211965.

It is an arithmetic number, because the mean of its divisors is an integer number (178738560).

Almost surely, 2^21020566770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020566770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34317803520).

21020566770 is an abundant number, since it is smaller than the sum of its proper divisors (47615040270).

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

21020566770 is a wasteful number, since it uses less digits than its factorization.

21020566770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092 (or 1080 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The spelling of 21020566770 in words is "twenty-one billion, twenty million, five hundred sixty-six thousand, seven hundred seventy".