20689267566 has 32 divisors (see below), whose sum is σ = 45401171328. Its totient is φ = 6233231840.

The previous prime is 20689267549. The next prime is 20689267589. The reversal of 20689267566 is 66576298602.

It is a congruent number.

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, 894576 + ... + 917411.

It is an arithmetic number, because the mean of its divisors is an integer number (1418786604).

Almost surely, 2^20689267566 is an apocalyptic number.

20689267566 is an abundant number, since it is smaller than the sum of its proper divisors (24711903762).

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

20689267566 is a wasteful number, since it uses less digits than its factorization.

20689267566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812176.

The product of its (nonzero) digits is 13063680, while the sum is 57.

The spelling of 20689267566 in words is "twenty billion, six hundred eighty-nine million, two hundred sixty-seven thousand, five hundred sixty-six".