72821823 has 4 divisors (see below), whose sum is σ = 97095768. Its totient is φ = 48547880.

The previous prime is 72821803. The next prime is 72821839. The reversal of 72821823 is 32812827.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72821823 - 2¹⁰ = 72820799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72821803) 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, 12136968 + ... + 12136973.

It is an arithmetic number, because the mean of its divisors is an integer number (24273942).

Almost surely, 2^72821823 is an apocalyptic number.

72821823 is a deficient number, since it is larger than the sum of its proper divisors (24273945).

72821823 is a wasteful number, since it uses less digits than its factorization.

72821823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24273944.

The product of its digits is 10752, while the sum is 33.

The square root of 72821823 is about 8533.5703547812. The cubic root of 72821823 is about 417.5936142522.

The spelling of 72821823 in words is "seventy-two million, eight hundred twenty-one thousand, eight hundred twenty-three".