72129961 has 8 divisors (see below), whose sum is σ = 73267200. Its totient is φ = 71000160.

The previous prime is 72129943. The next prime is 72129971. The reversal of 72129961 is 16992127.

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 72129961 - 2¹⁷ = 71998889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72129961.

It is not an unprimeable number, because it can be changed into a prime (72129971) 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 7 ways as a sum of consecutive naturals, for example, 19576 + ... + 22966.

It is an arithmetic number, because the mean of its divisors is an integer number (9158400).

Almost surely, 2^72129961 is an apocalyptic number.

It is an amenable number.

72129961 is a deficient number, since it is larger than the sum of its proper divisors (1137239).

72129961 is a wasteful number, since it uses less digits than its factorization.

72129961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3719.

The product of its digits is 13608, while the sum is 37.

The square root of 72129961 is about 8492.9359470091. The cubic root of 72129961 is about 416.2669195057.

The spelling of 72129961 in words is "seventy-two million, one hundred twenty-nine thousand, nine hundred sixty-one".