77985967 has 2 divisors, whose sum is σ = 77985968. Its totient is φ = 77985966.

The previous prime is 77985907. The next prime is 77985979. The reversal of 77985967 is 76958977.

It is a strong prime.

It is an emirp because it is prime and its reverse (76958977) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77985967 - 2⁷ = 77985839 is a prime.

It is a super-2 number, since 2×77985967² = 12163622097850178, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77985907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38992983 + 38992984.

It is an arithmetic number, because the mean of its divisors is an integer number (38992984).

Almost surely, 2^77985967 is an apocalyptic number.

77985967 is a deficient number, since it is larger than the sum of its proper divisors (1).

77985967 is an equidigital number, since it uses as much as digits as its factorization.

77985967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6667920, while the sum is 58.

The square root of 77985967 is about 8830.9663684107. The cubic root of 77985967 is about 427.2402434624.

The spelling of 77985967 in words is "seventy-seven million, nine hundred eighty-five thousand, nine hundred sixty-seven".