21272486664 has 128 divisors (see below), whose sum is σ = 64167626880. Its totient is φ = 5789491200.

The previous prime is 21272486647. The next prime is 21272486681. The reversal of 21272486664 is 46668427212.

It is an interprime number because it is at equal distance from previous prime (21272486647) and next prime (21272486681).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43224 + ... + 210744.

It is an arithmetic number, because the mean of its divisors is an integer number (501309585).

Almost surely, 2^21272486664 is an apocalyptic number.

21272486664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21272486664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32083813440).

21272486664 is an abundant number, since it is smaller than the sum of its proper divisors (42895140216).

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

21272486664 is a wasteful number, since it uses less digits than its factorization.

21272486664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167591 (or 167587 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 48.

The spelling of 21272486664 in words is "twenty-one billion, two hundred seventy-two million, four hundred eighty-six thousand, six hundred sixty-four".