72821684 has 12 divisors (see below), whose sum is σ = 137240964. Its totient is φ = 33609984.

The previous prime is 72821681. The next prime is 72821687. The reversal of 72821684 is 48612827.

It is an interprime number because it is at equal distance from previous prime (72821681) and next prime (72821687).

It can be written as a sum of positive squares in 2 ways, for example, as 39413284 + 33408400 = 6278^2 + 5780^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72821681) 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, 700157 + ... + 700260.

It is an arithmetic number, because the mean of its divisors is an integer number (11436747).

Almost surely, 2^72821684 is an apocalyptic number.

It is an amenable number.

72821684 is a deficient number, since it is larger than the sum of its proper divisors (64419280).

72821684 is a wasteful number, since it uses less digits than its factorization.

72821684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1400434 (or 1400432 counting only the distinct ones).

The product of its digits is 43008, while the sum is 38.

The square root of 72821684 is about 8533.5622104722. The cubic root of 72821684 is about 417.5933485555.

The spelling of 72821684 in words is "seventy-two million, eight hundred twenty-one thousand, six hundred eighty-four".