77861197 has 2 divisors, whose sum is σ = 77861198. Its totient is φ = 77861196.

The previous prime is 77861191. The next prime is 77861239. The reversal of 77861197 is 79116877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77774761 + 86436 = 8819^2 + 294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77861197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77861191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38930598 + 38930599.

It is an arithmetic number, because the mean of its divisors is an integer number (38930599).

Almost surely, 2^77861197 is an apocalyptic number.

It is an amenable number.

77861197 is a deficient number, since it is larger than the sum of its proper divisors (1).

77861197 is an equidigital number, since it uses as much as digits as its factorization.

77861197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 46.

The square root of 77861197 is about 8823.8991948004. The cubic root of 77861197 is about 427.0122741619.

The spelling of 77861197 in words is "seventy-seven million, eight hundred sixty-one thousand, one hundred ninety-seven".