78791077381 has 2 divisors, whose sum is σ = 78791077382. Its totient is φ = 78791077380.

The previous prime is 78791077357. The next prime is 78791077397. The reversal of 78791077381 is 18377019787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41988108100 + 36802969281 = 204910^2 + 191841^2 .

It is a cyclic number.

It is not a de Polignac number, because 78791077381 - 2⁹ = 78791076869 is a prime.

It is a super-2 number, since 2×78791077381² (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 (78791077481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39395538690 + 39395538691.

It is an arithmetic number, because the mean of its divisors is an integer number (39395538691).

Almost surely, 2^78791077381 is an apocalyptic number.

It is an amenable number.

78791077381 is a deficient number, since it is larger than the sum of its proper divisors (1).

78791077381 is an equidigital number, since it uses as much as digits as its factorization.

78791077381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4148928, while the sum is 58.

The spelling of 78791077381 in words is "seventy-eight billion, seven hundred ninety-one million, seventy-seven thousand, three hundred eighty-one".