72881649 has 6 divisors (see below), whose sum is σ = 105273506. Its totient is φ = 48587760.

The previous prime is 72881647. The next prime is 72881681. The reversal of 72881649 is 94618827.

It can be written as a sum of positive squares in only one way, i.e., 53802225 + 19079424 = 7335^2 + 4368^2 .

It is not a de Polignac number, because 72881649 - 2¹ = 72881647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72881647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4048972 + ... + 4048989.

Almost surely, 2^72881649 is an apocalyptic number.

It is an amenable number.

72881649 is a deficient number, since it is larger than the sum of its proper divisors (32391857).

72881649 is a wasteful number, since it uses less digits than its factorization.

72881649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8097967 (or 8097964 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 72881649 is about 8537.0749674581. The cubic root of 72881649 is about 417.7079394923.

It can be divided in two parts, 72 and 881649, that added together give a square (881721 = 939²).

The spelling of 72881649 in words is "seventy-two million, eight hundred eighty-one thousand, six hundred forty-nine".