78571649 has 12 divisors (see below), whose sum is σ = 85975596. Its totient is φ = 71764992.

The previous prime is 78571613. The next prime is 78571667. The reversal of 78571649 is 94617587.

It can be written as a sum of positive squares in 6 ways, for example, as 3489424 + 75082225 = 1868^2 + 8665^2 .

It is not a de Polignac number, because 78571649 - 2⁸ = 78571393 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78571679) 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, 13997 + ... + 18789.

It is an arithmetic number, because the mean of its divisors is an integer number (7164633).

Almost surely, 2^78571649 is an apocalyptic number.

It is an amenable number.

78571649 is a deficient number, since it is larger than the sum of its proper divisors (7403947).

78571649 is a wasteful number, since it uses less digits than its factorization.

78571649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4916 (or 4903 counting only the distinct ones).

The product of its digits is 423360, while the sum is 47.

The square root of 78571649 is about 8864.0650381188. The cubic root of 78571649 is about 428.3071153673.

The spelling of 78571649 in words is "seventy-eight million, five hundred seventy-one thousand, six hundred forty-nine".