78671691 has 12 divisors (see below), whose sum is σ = 129870832. Its totient is φ = 44955216.

The previous prime is 78671689. The next prime is 78671711. The reversal of 78671691 is 19617687.

It is not a de Polignac number, because 78671691 - 2¹ = 78671689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78671641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 624316 + ... + 624441.

Almost surely, 2^78671691 is an apocalyptic number.

78671691 is a deficient number, since it is larger than the sum of its proper divisors (51199141).

78671691 is a wasteful number, since it uses less digits than its factorization.

78671691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248770 (or 1248767 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 78671691 is about 8869.7063649255. The cubic root of 78671691 is about 428.4888201256.

The spelling of 78671691 in words is "seventy-eight million, six hundred seventy-one thousand, six hundred ninety-one".