72721615 has 8 divisors (see below), whose sum is σ = 87822720. Its totient is φ = 57806112.

The previous prime is 72721591. The next prime is 72721673. The reversal of 72721615 is 51612727.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72721615 - 2⁷ = 72721487 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45535 + ... + 47104.

It is an arithmetic number, because the mean of its divisors is an integer number (10977840).

Almost surely, 2^72721615 is an apocalyptic number.

72721615 is a deficient number, since it is larger than the sum of its proper divisors (15101105).

72721615 is a wasteful number, since it uses less digits than its factorization.

72721615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92801.

The product of its digits is 5880, while the sum is 31.

The square root of 72721615 is about 8527.6969341083. The cubic root of 72721615 is about 417.4019801682.

The spelling of 72721615 in words is "seventy-two million, seven hundred twenty-one thousand, six hundred fifteen".