72689021 has 4 divisors (see below), whose sum is σ = 72739392. Its totient is φ = 72638652.

The previous prime is 72688999. The next prime is 72689027. The reversal of 72689021 is 12098627.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-72689021 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 (72689027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22955 + ... + 25928.

It is an arithmetic number, because the mean of its divisors is an integer number (18184848).

Almost surely, 2^72689021 is an apocalyptic number.

It is an amenable number.

72689021 is a deficient number, since it is larger than the sum of its proper divisors (50371).

72689021 is a wasteful number, since it uses less digits than its factorization.

72689021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50370.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 72689021 is about 8525.7856529472. The cubic root of 72689021 is about 417.3396106640.

The spelling of 72689021 in words is "seventy-two million, six hundred eighty-nine thousand, twenty-one".