20021171564 has 12 divisors (see below), whose sum is σ = 36167277888. Its totient is φ = 9687663600.

The previous prime is 20021171519. The next prime is 20021171581. The reversal of 20021171564 is 46517112002.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80730407 + ... + 80730654.

It is an arithmetic number, because the mean of its divisors is an integer number (3013939824).

Almost surely, 2^20021171564 is an apocalyptic number.

It is an amenable number.

20021171564 is a deficient number, since it is larger than the sum of its proper divisors (16146106324).

20021171564 is a wasteful number, since it uses less digits than its factorization.

20021171564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161461096 (or 161461094 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

Adding to 20021171564 its reverse (46517112002), we get a palindrome (66538283566).

The spelling of 20021171564 in words is "twenty billion, twenty-one million, one hundred seventy-one thousand, five hundred sixty-four".