72207821 has 12 divisors (see below), whose sum is σ = 84153888. Its totient is φ = 61776792.

The previous prime is 72207763. The next prime is 72207827. The reversal of 72207821 is 12870227.

It is not a de Polignac number, because 72207821 - 2¹⁸ = 71945677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72207827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34610 + ... + 36636.

It is an arithmetic number, because the mean of its divisors is an integer number (7012824).

Almost surely, 2^72207821 is an apocalyptic number.

It is an amenable number.

72207821 is a deficient number, since it is larger than the sum of its proper divisors (11946067).

72207821 is a wasteful number, since it uses less digits than its factorization.

72207821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2768 (or 2761 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 72207821 is about 8497.5185201328. The cubic root of 72207821 is about 416.4166441007.

The spelling of 72207821 in words is "seventy-two million, two hundred seven thousand, eight hundred twenty-one".