72409966281 has 45 divisors (see below), whose sum is σ = 112135286263. Its totient is φ = 46563506640.

The previous prime is 72409966267. The next prime is 72409966301. The reversal of 72409966281 is 18266990427.

The square root of 72409966281 is 269091.

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

72409966281 is a `hidden beast` number, since 7 + 2 + 4 + 0 + 9 + 9 + 6 + 628 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 37970029881 + 34439936400 = 194859^2 + 185580^2 .

It is not a de Polignac number, because 72409966281 - 2⁵ = 72409966249 is a prime.

It is a super-2 number, since 2×72409966281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72409966231) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 70232236 + ... + 70233266.

Almost surely, 2^72409966281 is an apocalyptic number.

72409966281 is the 269091-st square number.

72409966281 is the 134546-th centered octagonal number.

It is an amenable number.

72409966281 is a deficient number, since it is larger than the sum of its proper divisors (39725319982).

72409966281 is an frugal number, since it uses more digits than its factorization.

72409966281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132 (or 1063 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 72409966281 in words is "seventy-two billion, four hundred nine million, nine hundred sixty-six thousand, two hundred eighty-one".