21002617272 has 128 divisors (see below), whose sum is σ = 64708761600. Its totient is φ = 5531839488.

The previous prime is 21002617267. The next prime is 21002617283. The reversal of 21002617272 is 27271620012.

It is a super-2 number, since 2×21002617272² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1760913 + ... + 1772799.

It is an arithmetic number, because the mean of its divisors is an integer number (505537200).

Almost surely, 2^21002617272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002617272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32354380800).

21002617272 is an abundant number, since it is smaller than the sum of its proper divisors (43706144328).

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

21002617272 is a wasteful number, since it uses less digits than its factorization.

21002617272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12725 (or 12721 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The spelling of 21002617272 in words is "twenty-one billion, two million, six hundred seventeen thousand, two hundred seventy-two".