78851977 has 2 divisors, whose sum is σ = 78851978. Its totient is φ = 78851976.

The previous prime is 78851951. The next prime is 78851987. The reversal of 78851977 is 77915887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50751376 + 28100601 = 7124^2 + 5301^2 .

It is a cyclic number.

It is not a de Polignac number, because 78851977 - 2⁷ = 78851849 is a prime.

It is not a weakly prime, because it can be changed into another prime (78851917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39425988 + 39425989.

It is an arithmetic number, because the mean of its divisors is an integer number (39425989).

Almost surely, 2^78851977 is an apocalyptic number.

It is an amenable number.

78851977 is a deficient number, since it is larger than the sum of its proper divisors (1).

78851977 is an equidigital number, since it uses as much as digits as its factorization.

78851977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 987840, while the sum is 52.

The square root of 78851977 is about 8879.8635687718. The cubic root of 78851977 is about 428.8158822904.

The spelling of 78851977 in words is "seventy-eight million, eight hundred fifty-one thousand, nine hundred seventy-seven".