78628997 has 4 divisors (see below), whose sum is σ = 78877356. Its totient is φ = 78380640.

The previous prime is 78628967. The next prime is 78628999. The reversal of 78628997 is 79982687.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79982687 = 359 ⋅222793.

It can be written as a sum of positive squares in 2 ways, for example, as 41589601 + 37039396 = 6449^2 + 6086^2 .

It is a cyclic number.

It is not a de Polignac number, because 78628997 - 2¹² = 78624901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78628999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123704 + ... + 124337.

It is an arithmetic number, because the mean of its divisors is an integer number (19719339).

Almost surely, 2^78628997 is an apocalyptic number.

It is an amenable number.

78628997 is a deficient number, since it is larger than the sum of its proper divisors (248359).

78628997 is a wasteful number, since it uses less digits than its factorization.

78628997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248358.

The product of its digits is 3048192, while the sum is 56.

The square root of 78628997 is about 8867.2993070044. The cubic root of 78628997 is about 428.4112945179.

The spelling of 78628997 in words is "seventy-eight million, six hundred twenty-eight thousand, nine hundred ninety-seven".