72897821 has 4 divisors (see below), whose sum is σ = 73776192. Its totient is φ = 72019452.

The previous prime is 72897791. The next prime is 72897823. The reversal of 72897821 is 12879827.

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 72897821 - 2¹⁰ = 72896797 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 (72897823) 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, 439061 + ... + 439226.

It is an arithmetic number, because the mean of its divisors is an integer number (18444048).

Almost surely, 2^72897821 is an apocalyptic number.

It is an amenable number.

72897821 is a deficient number, since it is larger than the sum of its proper divisors (878371).

72897821 is an equidigital number, since it uses as much as digits as its factorization.

72897821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878370.

The product of its digits is 112896, while the sum is 44.

The square root of 72897821 is about 8538.0220777414. The cubic root of 72897821 is about 417.7388328347.

The spelling of 72897821 in words is "seventy-two million, eight hundred ninety-seven thousand, eight hundred twenty-one".