21064436766 has 12 divisors (see below), whose sum is σ = 45639613032. Its totient is φ = 7021478916.

The previous prime is 21064436741. The next prime is 21064436801. The reversal of 21064436766 is 66763446012.

It is a happy number.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 585123226 + ... + 585123261.

It is an arithmetic number, because the mean of its divisors is an integer number (3803301086).

Almost surely, 2^21064436766 is an apocalyptic number.

21064436766 is an abundant number, since it is smaller than the sum of its proper divisors (24575176266).

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

21064436766 is a wasteful number, since it uses less digits than its factorization.

21064436766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170246495 (or 1170246492 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 45.

The spelling of 21064436766 in words is "twenty-one billion, sixty-four million, four hundred thirty-six thousand, seven hundred sixty-six".