72412121 has 2 divisors, whose sum is σ = 72412122. Its totient is φ = 72412120.

The previous prime is 72412099. The next prime is 72412133. The reversal of 72412121 is 12121427.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41731600 + 30680521 = 6460^2 + 5539^2 .

It is an emirp because it is prime and its reverse (12121427) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72412121 - 2¹⁸ = 72149977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72412093 and 72412102.

It is not a weakly prime, because it can be changed into another prime (72412141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36206060 + 36206061.

It is an arithmetic number, because the mean of its divisors is an integer number (36206061).

Almost surely, 2^72412121 is an apocalyptic number.

It is an amenable number.

72412121 is a deficient number, since it is larger than the sum of its proper divisors (1).

72412121 is an equidigital number, since it uses as much as digits as its factorization.

72412121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 224, while the sum is 20.

The square root of 72412121 is about 8509.5311856764. The cubic root of 72412121 is about 416.8090014702.

Adding to 72412121 its reverse (12121427), we get a palindrome (84533548).

The spelling of 72412121 in words is "seventy-two million, four hundred twelve thousand, one hundred twenty-one".