72121545 has 24 divisors (see below), whose sum is σ = 125588736. Its totient is φ = 38287008.

The previous prime is 72121529. The next prime is 72121559. The reversal of 72121545 is 54512127.

It is not a de Polignac number, because 72121545 - 2⁴ = 72121529 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 6442 + ... + 13628.

It is an arithmetic number, because the mean of its divisors is an integer number (5232864).

Almost surely, 2^72121545 is an apocalyptic number.

It is an amenable number.

72121545 is a deficient number, since it is larger than the sum of its proper divisors (53467191).

72121545 is a wasteful number, since it uses less digits than its factorization.

72121545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7421 (or 7418 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 72121545 is about 8492.4404619638. The cubic root of 72121545 is about 416.2507291062.

The spelling of 72121545 in words is "seventy-two million, one hundred twenty-one thousand, five hundred forty-five".