72872821 has 4 divisors (see below), whose sum is σ = 83283232. Its totient is φ = 62462412.

The previous prime is 72872819. The next prime is 72872837. The reversal of 72872821 is 12827827.

It is a happy number.

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 72872821 - 2¹ = 72872819 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 (72872851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5205195 + ... + 5205208.

It is an arithmetic number, because the mean of its divisors is an integer number (20820808).

Almost surely, 2^72872821 is an apocalyptic number.

It is an amenable number.

72872821 is a deficient number, since it is larger than the sum of its proper divisors (10410411).

72872821 is a wasteful number, since it uses less digits than its factorization.

72872821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10410410.

The product of its digits is 25088, while the sum is 37.

The square root of 72872821 is about 8536.5579128827. The cubic root of 72872821 is about 417.6910734515.

The spelling of 72872821 in words is "seventy-two million, eight hundred seventy-two thousand, eight hundred twenty-one".