72320451 has 24 divisors (see below), whose sum is σ = 112669440. Its totient is φ = 40420752.

The previous prime is 72320447. The next prime is 72320467. The reversal of 72320451 is 15402327.

It is not a de Polignac number, because 72320451 - 2² = 72320447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72320411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45610 + ... + 47168.

It is an arithmetic number, because the mean of its divisors is an integer number (4694560).

Almost surely, 2^72320451 is an apocalyptic number.

72320451 is a deficient number, since it is larger than the sum of its proper divisors (40348989).

72320451 is a wasteful number, since it uses less digits than its factorization.

72320451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663 (or 1616 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 72320451 is about 8504.1431667159. The cubic root of 72320451 is about 416.6330409842.

Adding to 72320451 its reverse (15402327), we get a palindrome (87722778).

It can be divided in two parts, 72320 and 451, that added together give a triangular number (72771 = T₃₈₁).

The spelling of 72320451 in words is "seventy-two million, three hundred twenty thousand, four hundred fifty-one".