20974531401616 has 135 divisors (see below), whose sum is σ = 45589365419481. Its totient is φ = 9343663160832.

The previous prime is 20974531401563. The next prime is 20974531401641. The reversal of 20974531401616 is 61610413547902.

The square root of 20974531401616 is 4579796.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 10125149456016 + 10849381945600 = 3182004^2 + 3293840^2 .

It is a super-2 number, since 2×20974531401616² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20974531401616.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6906330850 + ... + 6906333886.

Almost surely, 2^{20974531401616} is an apocalyptic number.

20974531401616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20974531401616 is the 4579796-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20974531401616

20974531401616 is an abundant number, since it is smaller than the sum of its proper divisors (24614834017865).

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

20974531401616 is an frugal number, since it uses more digits than its factorization.

20974531401616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6166 (or 3081 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 49.

The spelling of 20974531401616 in words is "twenty trillion, nine hundred seventy-four billion, five hundred thirty-one million, four hundred one thousand, six hundred sixteen".