72661457 has 4 divisors (see below), whose sum is σ = 79267056. Its totient is φ = 66055860.

The previous prime is 72661447. The next prime is 72661481. The reversal of 72661457 is 75416627.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72661457 - 2⁴ = 72661441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72661457.

It is not an unprimeable number, because it can be changed into a prime (72661447) 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 3 ways as a sum of consecutive naturals, for example, 3302783 + ... + 3302804.

It is an arithmetic number, because the mean of its divisors is an integer number (19816764).

Almost surely, 2^72661457 is an apocalyptic number.

It is an amenable number.

72661457 is a deficient number, since it is larger than the sum of its proper divisors (6605599).

72661457 is a wasteful number, since it uses less digits than its factorization.

72661457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6605598.

The product of its digits is 70560, while the sum is 38.

The square root of 72661457 is about 8524.1689917551. The cubic root of 72661457 is about 417.2868516492.

The spelling of 72661457 in words is "seventy-two million, six hundred sixty-one thousand, four hundred fifty-seven".