72010021 has 4 divisors (see below), whose sum is σ = 72052192. Its totient is φ = 71967852.

The previous prime is 72010009. The next prime is 72010027. The reversal of 72010021 is 12001027.

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 72010021 - 2²⁵ = 38455589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72009983 and 72010010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72010027) 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, 18411 + ... + 21976.

It is an arithmetic number, because the mean of its divisors is an integer number (18013048).

Almost surely, 2^72010021 is an apocalyptic number.

It is an amenable number.

72010021 is a deficient number, since it is larger than the sum of its proper divisors (42171).

72010021 is a wasteful number, since it uses less digits than its factorization.

72010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42170.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 72010021 is about 8485.8718467816. The cubic root of 72010021 is about 416.0360641965.

Adding to 72010021 its reverse (12001027), we get a palindrome (84011048).

The spelling of 72010021 in words is "seventy-two million, ten thousand, twenty-one".