72121616 has 40 divisors (see below), whose sum is σ = 169096320. Its totient is φ = 29090304.

The previous prime is 72121603. The next prime is 72121631. The reversal of 72121616 is 61612127.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17036 + ... + 20843.

It is an arithmetic number, because the mean of its divisors is an integer number (4227408).

Almost surely, 2^72121616 is an apocalyptic number.

It is an amenable number.

72121616 is an abundant number, since it is smaller than the sum of its proper divisors (96974704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72121616 is a wasteful number, since it uses less digits than its factorization.

72121616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37911 (or 37905 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 72121616 is about 8492.4446421510. Note that the first 3 decimals coincide. The cubic root of 72121616 is about 416.2508656987.

The spelling of 72121616 in words is "seventy-two million, one hundred twenty-one thousand, six hundred sixteen".