72021513 has 4 divisors (see below), whose sum is σ = 96028688. Its totient is φ = 48014340.

The previous prime is 72021493. The next prime is 72021527. The reversal of 72021513 is 31512027.

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 not a de Polignac number, because 72021513 - 2¹³ = 72013321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72021513.

It is not an unprimeable number, because it can be changed into a prime (72021563) 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, 12003583 + ... + 12003588.

It is an arithmetic number, because the mean of its divisors is an integer number (24007172).

Almost surely, 2^72021513 is an apocalyptic number.

It is an amenable number.

72021513 is a deficient number, since it is larger than the sum of its proper divisors (24007175).

72021513 is a wasteful number, since it uses less digits than its factorization.

72021513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24007174.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 72021513 is about 8486.5489452427. The cubic root of 72021513 is about 416.0581945985.

The spelling of 72021513 in words is "seventy-two million, twenty-one thousand, five hundred thirteen".