78077577989 has 2 divisors, whose sum is σ = 78077577990. Its totient is φ = 78077577988.

The previous prime is 78077577947. The next prime is 78077578043. The reversal of 78077577989 is 98977577087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57209464225 + 20868113764 = 239185^2 + 144458^2 .

It is a cyclic number.

It is not a de Polignac number, because 78077577989 - 2²⁴ = 78060800773 is a prime.

It is a super-2 number, since 2×78077577989² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78077777989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39038788994 + 39038788995.

It is an arithmetic number, because the mean of its divisors is an integer number (39038788995).

Almost surely, 2^78077577989 is an apocalyptic number.

It is an amenable number.

78077577989 is a deficient number, since it is larger than the sum of its proper divisors (1).

78077577989 is an equidigital number, since it uses as much as digits as its factorization.

78077577989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435637440, while the sum is 74.

The spelling of 78077577989 in words is "seventy-eight billion, seventy-seven million, five hundred seventy-seven thousand, nine hundred eighty-nine".