72660121 has 2 divisors, whose sum is σ = 72660122. Its totient is φ = 72660120.

The previous prime is 72660113. The next prime is 72660149. The reversal of 72660121 is 12106627.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48108096 + 24552025 = 6936^2 + 4955^2 .

It is a cyclic number.

It is not a de Polignac number, because 72660121 - 2³ = 72660113 is a prime.

It is not a weakly prime, because it can be changed into another prime (72660221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36330060 + 36330061.

It is an arithmetic number, because the mean of its divisors is an integer number (36330061).

Almost surely, 2^72660121 is an apocalyptic number.

It is an amenable number.

72660121 is a deficient number, since it is larger than the sum of its proper divisors (1).

72660121 is an equidigital number, since it uses as much as digits as its factorization.

72660121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 72660121 is about 8524.0906259847. The cubic root of 72660121 is about 417.2842941326.

Adding to 72660121 its reverse (12106627), we get a palindrome (84766748).

The spelling of 72660121 in words is "seventy-two million, six hundred sixty thousand, one hundred twenty-one".