76521257 has 2 divisors, whose sum is σ = 76521258. Its totient is φ = 76521256.

The previous prime is 76521251. The next prime is 76521259. The reversal of 76521257 is 75212567.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45373696 + 31147561 = 6736^2 + 5581^2 .

It is a cyclic number.

It is not a de Polignac number, because 76521257 - 2¹⁴ = 76504873 is a prime.

Together with 76521259, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (76521251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38260628 + 38260629.

It is an arithmetic number, because the mean of its divisors is an integer number (38260629).

Almost surely, 2^76521257 is an apocalyptic number.

It is an amenable number.

76521257 is a deficient number, since it is larger than the sum of its proper divisors (1).

76521257 is an equidigital number, since it uses as much as digits as its factorization.

76521257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29400, while the sum is 35.

The square root of 76521257 is about 8747.6429396724. The cubic root of 76521257 is about 424.5485531563.

It can be divided in two parts, 765 and 21257, that added together give a palindrome (22022).

The spelling of 76521257 in words is "seventy-six million, five hundred twenty-one thousand, two hundred fifty-seven".