72615321 has 24 divisors (see below), whose sum is σ = 111983040. Its totient is φ = 45208800.

The previous prime is 72615317. The next prime is 72615341. The reversal of 72615321 is 12351627.

It is a happy number.

72615321 is a `hidden beast` number, since 72 + 61 + 532 + 1 = 666.

It is not a de Polignac number, because 72615321 - 2² = 72615317 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72615341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9151 + ... + 15131.

It is an arithmetic number, because the mean of its divisors is an integer number (4665960).

Almost surely, 2^72615321 is an apocalyptic number.

72615321 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

72615321 is a deficient number, since it is larger than the sum of its proper divisors (39367719).

72615321 is a wasteful number, since it uses less digits than its factorization.

72615321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6077 (or 6074 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 72615321 is about 8521.4623744989. The cubic root of 72615321 is about 417.1985149387.

Adding to 72615321 its reverse (12351627), we get a palindrome (84966948).

The spelling of 72615321 in words is "seventy-two million, six hundred fifteen thousand, three hundred twenty-one".