72949681 has 12 divisors (see below), whose sum is σ = 87155508. Its totient is φ = 60836832.

The previous prime is 72949673. The next prime is 72949693. The reversal of 72949681 is 18694927.

It can be written as a sum of positive squares in 2 ways, for example, as 60699681 + 12250000 = 7791^2 + 3500^2 .

It is not a de Polignac number, because 72949681 - 2³ = 72949673 is a prime.

It is a super-2 number, since 2×72949681² = 10643311916003522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72949661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18306 + ... + 21931.

It is an arithmetic number, because the mean of its divisors is an integer number (7262959).

Almost surely, 2^72949681 is an apocalyptic number.

It is an amenable number.

72949681 is a deficient number, since it is larger than the sum of its proper divisors (14205827).

72949681 is a wasteful number, since it uses less digits than its factorization.

72949681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40288 (or 40281 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The square root of 72949681 is about 8541.0585409538. The cubic root of 72949681 is about 417.8378700913.

The spelling of 72949681 in words is "seventy-two million, nine hundred forty-nine thousand, six hundred eighty-one".