72712421 has 2 divisors, whose sum is σ = 72712422. Its totient is φ = 72712420.

The previous prime is 72712397. The next prime is 72712433. The reversal of 72712421 is 12421727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54316900 + 18395521 = 7370^2 + 4289^2 .

It is an emirp because it is prime and its reverse (12421727) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72712421 - 2⁶ = 72712357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72712481) 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 as a sum of consecutive naturals, namely, 36356210 + 36356211.

It is an arithmetic number, because the mean of its divisors is an integer number (36356211).

Almost surely, 2^72712421 is an apocalyptic number.

It is an amenable number.

72712421 is a deficient number, since it is larger than the sum of its proper divisors (1).

72712421 is an equidigital number, since it uses as much as digits as its factorization.

72712421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1568, while the sum is 26.

The square root of 72712421 is about 8527.1578500694. The cubic root of 72712421 is about 417.3843890868.

The spelling of 72712421 in words is "seventy-two million, seven hundred twelve thousand, four hundred twenty-one".