78551687 has 2 divisors, whose sum is σ = 78551688. Its totient is φ = 78551686.

The previous prime is 78551657. The next prime is 78551699. The reversal of 78551687 is 78615587.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78551687 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 (78551657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39275843 + 39275844.

It is an arithmetic number, because the mean of its divisors is an integer number (39275844).

Almost surely, 2^78551687 is an apocalyptic number.

78551687 is a deficient number, since it is larger than the sum of its proper divisors (1).

78551687 is an equidigital number, since it uses as much as digits as its factorization.

78551687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 470400, while the sum is 47.

The square root of 78551687 is about 8862.9389595100. The cubic root of 78551687 is about 428.2708402354.

The spelling of 78551687 in words is "seventy-eight million, five hundred fifty-one thousand, six hundred eighty-seven".