21266375064 has 32 divisors (see below), whose sum is σ = 57999205440. Its totient is φ = 6444356000.

The previous prime is 21266375057. The next prime is 21266375077. The reversal of 21266375064 is 46057366212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40276962 + ... + 40277489.

It is an arithmetic number, because the mean of its divisors is an integer number (1812475170).

Almost surely, 2^21266375064 is an apocalyptic number.

21266375064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21266375064 is an abundant number, since it is smaller than the sum of its proper divisors (36732830376).

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

21266375064 is a wasteful number, since it uses less digits than its factorization.

21266375064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80554471 (or 80554467 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 42.

The spelling of 21266375064 in words is "twenty-one billion, two hundred sixty-six million, three hundred seventy-five thousand, sixty-four".