72897761 has 2 divisors, whose sum is σ = 72897762. Its totient is φ = 72897760.

The previous prime is 72897749. The next prime is 72897763. The reversal of 72897761 is 16779827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72165025 + 732736 = 8495^2 + 856^2 .

It is a cyclic number.

It is not a de Polignac number, because 72897761 - 2⁶ = 72897697 is a prime.

It is a Sophie Germain prime.

Together with 72897763, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (72897763) 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, 36448880 + 36448881.

It is an arithmetic number, because the mean of its divisors is an integer number (36448881).

Almost surely, 2^72897761 is an apocalyptic number.

It is an amenable number.

72897761 is a deficient number, since it is larger than the sum of its proper divisors (1).

72897761 is an equidigital number, since it uses as much as digits as its factorization.

72897761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 296352, while the sum is 47.

The square root of 72897761 is about 8538.0185640463. The cubic root of 72897761 is about 417.7387182252.

It can be divided in two parts, 728 and 97761, that added together give a palindrome (98489).

The spelling of 72897761 in words is "seventy-two million, eight hundred ninety-seven thousand, seven hundred sixty-one".