72338943681 has 9 divisors (see below), whose sum is σ = 104490750819. Its totient is φ = 48225424536.

The previous prime is 72338943653. The next prime is 72338943689. The reversal of 72338943681 is 18634983327.

The square root of 72338943681 is 268959.

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

It can be written as a sum of positive squares in only one way, i.e., 67753487025 + 4585456656 = 260295^2 + 67716^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 72338943681 - 2⁹ = 72338943169 is a prime.

It is a super-2 number, since 2×72338943681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72338943689) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 762051 + ... + 851703.

Almost surely, 2^72338943681 is an apocalyptic number.

72338943681 is the 268959-th square number.

72338943681 is the 134480-th centered octagonal number.

It is an amenable number.

72338943681 is a deficient number, since it is larger than the sum of its proper divisors (32151807138).

72338943681 is an frugal number, since it uses more digits than its factorization.

72338943681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179312 (or 89656 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 54.

The spelling of 72338943681 in words is "seventy-two billion, three hundred thirty-eight million, nine hundred forty-three thousand, six hundred eighty-one".