77975257849 has 2 divisors, whose sum is σ = 77975257850. Its totient is φ = 77975257848.

The previous prime is 77975257817. The next prime is 77975257853. The reversal of 77975257849 is 94875257977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68797617849 + 9177640000 = 262293^2 + 95800^2 .

It is a cyclic number.

It is not a de Polignac number, because 77975257849 - 2⁵ = 77975257817 is a prime.

It is a super-2 number, since 2×77975257849² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (77975257859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38987628924 + 38987628925.

It is an arithmetic number, because the mean of its divisors is an integer number (38987628925).

Almost surely, 2^77975257849 is an apocalyptic number.

It is an amenable number.

77975257849 is a deficient number, since it is larger than the sum of its proper divisors (1).

77975257849 is an equidigital number, since it uses as much as digits as its factorization.

77975257849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311169600, while the sum is 70.

The spelling of 77975257849 in words is "seventy-seven billion, nine hundred seventy-five million, two hundred fifty-seven thousand, eight hundred forty-nine".