78997947 has 12 divisors (see below), whose sum is σ = 122527656. Its totient is φ = 45141600.

The previous prime is 78997883. The next prime is 78997949. The reversal of 78997947 is 74979987.

It is not a de Polignac number, because 78997947 - 2⁶ = 78997883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78997949) 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, 268554 + ... + 268847.

It is an arithmetic number, because the mean of its divisors is an integer number (10210638).

Almost surely, 2^78997947 is an apocalyptic number.

78997947 is a deficient number, since it is larger than the sum of its proper divisors (43529709).

78997947 is a wasteful number, since it uses less digits than its factorization.

78997947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537418 (or 537411 counting only the distinct ones).

The product of its digits is 8001504, while the sum is 60.

The square root of 78997947 is about 8888.0789262922. The cubic root of 78997947 is about 429.0803257525.

The spelling of 78997947 in words is "seventy-eight million, nine hundred ninety-seven thousand, nine hundred forty-seven".