72479021 has 4 divisors (see below), whose sum is σ = 74246844. Its totient is φ = 70711200.

The previous prime is 72479009. The next prime is 72479047. The reversal of 72479021 is 12097427.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17556100 + 54922921 = 4190^2 + 7411^2 .

It is a cyclic number.

It is not a de Polignac number, because 72479021 - 2²² = 68284717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72479051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883850 + ... + 883931.

It is an arithmetic number, because the mean of its divisors is an integer number (18561711).

Almost surely, 2^72479021 is an apocalyptic number.

It is an amenable number.

72479021 is a deficient number, since it is larger than the sum of its proper divisors (1767823).

72479021 is a wasteful number, since it uses less digits than its factorization.

72479021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767822.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 72479021 is about 8513.4611645323. The cubic root of 72479021 is about 416.9373222490.

The spelling of 72479021 in words is "seventy-two million, four hundred seventy-nine thousand, twenty-one".