72428621 has 4 divisors (see below), whose sum is σ = 73105632. Its totient is φ = 71751612.

The previous prime is 72428611. The next prime is 72428623. The reversal of 72428621 is 12682427.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12682427 = 401 ⋅31627.

It is a cyclic number.

It is not a de Polignac number, because 72428621 - 2⁶ = 72428557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72428623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338345 + ... + 338558.

It is an arithmetic number, because the mean of its divisors is an integer number (18276408).

Almost surely, 2^72428621 is an apocalyptic number.

It is an amenable number.

72428621 is a deficient number, since it is larger than the sum of its proper divisors (677011).

72428621 is a wasteful number, since it uses less digits than its factorization.

72428621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677010.

The product of its digits is 10752, while the sum is 32.

The square root of 72428621 is about 8510.5006315727. The cubic root of 72428621 is about 416.8406574330.

The spelling of 72428621 in words is "seventy-two million, four hundred twenty-eight thousand, six hundred twenty-one".