72500121 has 12 divisors (see below), whose sum is σ = 110882772. Its totient is φ = 45490176.

The previous prime is 72500111. The next prime is 72500149. The reversal of 72500121 is 12100527.

It can be written as a sum of positive squares in 2 ways, for example, as 47610000 + 24890121 = 6900^2 + 4989^2 .

It is not a de Polignac number, because 72500121 - 2⁷ = 72499993 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 72500094 and 72500103.

It is not an unprimeable number, because it can be changed into a prime (72500101) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 236776 + ... + 237081.

It is an arithmetic number, because the mean of its divisors is an integer number (9240231).

Almost surely, 2^72500121 is an apocalyptic number.

It is an amenable number.

72500121 is a deficient number, since it is larger than the sum of its proper divisors (38382651).

72500121 is a wasteful number, since it uses less digits than its factorization.

72500121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473880 (or 473877 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 72500121 is about 8514.7002883249. The cubic root of 72500121 is about 416.9777777437.

Adding to 72500121 its reverse (12100527), we get a palindrome (84600648).

The spelling of 72500121 in words is "seventy-two million, five hundred thousand, one hundred twenty-one".