87781277 has 2 divisors, whose sum is σ = 87781278. Its totient is φ = 87781276.

The previous prime is 87781249. The next prime is 87781301. The reversal of 87781277 is 77218778.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87123556 + 657721 = 9334^2 + 811^2 .

It is a cyclic number.

It is not a de Polignac number, because 87781277 - 2²² = 83586973 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87781237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43890638 + 43890639.

It is an arithmetic number, because the mean of its divisors is an integer number (43890639).

Almost surely, 2^87781277 is an apocalyptic number.

It is an amenable number.

87781277 is a deficient number, since it is larger than the sum of its proper divisors (1).

87781277 is an equidigital number, since it uses as much as digits as its factorization.

87781277 is an evil number, because the sum of its binary digits is even.

The product of its digits is 307328, while the sum is 47.

The square root of 87781277 is about 9369.1662916185. The cubic root of 87781277 is about 444.4272005648.

The spelling of 87781277 in words is "eighty-seven million, seven hundred eighty-one thousand, two hundred seventy-seven".