76678781 has 2 divisors, whose sum is σ = 76678782. Its totient is φ = 76678780.

The previous prime is 76678759. The next prime is 76678807. The reversal of 76678781 is 18787667.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76562500 + 116281 = 8750^2 + 341^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-76678781 is a prime.

It is a super-2 number, since 2×76678781² = 11759270911291922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (76678081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38339390 + 38339391.

It is an arithmetic number, because the mean of its divisors is an integer number (38339391).

Almost surely, 2^76678781 is an apocalyptic number.

It is an amenable number.

76678781 is a deficient number, since it is larger than the sum of its proper divisors (1).

76678781 is an equidigital number, since it uses as much as digits as its factorization.

76678781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 790272, while the sum is 50.

The square root of 76678781 is about 8756.6421075661. The cubic root of 76678781 is about 424.8396737825.

The spelling of 76678781 in words is "seventy-six million, six hundred seventy-eight thousand, seven hundred eighty-one".