72721487 has 2 divisors, whose sum is σ = 72721488. Its totient is φ = 72721486.

The previous prime is 72721483. The next prime is 72721511. The reversal of 72721487 is 78412727.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72721487 - 2² = 72721483 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72721487.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72721483) 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, 36360743 + 36360744.

It is an arithmetic number, because the mean of its divisors is an integer number (36360744).

Almost surely, 2^72721487 is an apocalyptic number.

72721487 is a deficient number, since it is larger than the sum of its proper divisors (1).

72721487 is an equidigital number, since it uses as much as digits as its factorization.

72721487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43904, while the sum is 38.

The square root of 72721487 is about 8527.6894291479. The cubic root of 72721487 is about 417.4017352731.

The spelling of 72721487 in words is "seventy-two million, seven hundred twenty-one thousand, four hundred eighty-seven".