72721511 has 2 divisors, whose sum is σ = 72721512. Its totient is φ = 72721510.

The previous prime is 72721487. The next prime is 72721547. The reversal of 72721511 is 11512727.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72721511 - 2⁶ = 72721447 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72721591) by changing a digit.

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 as a sum of consecutive naturals, namely, 36360755 + 36360756.

It is an arithmetic number, because the mean of its divisors is an integer number (36360756).

Almost surely, 2^72721511 is an apocalyptic number.

72721511 is a deficient number, since it is larger than the sum of its proper divisors (1).

72721511 is an equidigital number, since it uses as much as digits as its factorization.

72721511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 980, while the sum is 26.

The square root of 72721511 is about 8527.6908363284. The cubic root of 72721511 is about 417.4017811910.

The spelling of 72721511 in words is "seventy-two million, seven hundred twenty-one thousand, five hundred eleven".