78606989 has 2 divisors, whose sum is σ = 78606990. Its totient is φ = 78606988.

The previous prime is 78606973. The next prime is 78607007. The reversal of 78606989 is 98960687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71690089 + 6916900 = 8467^2 + 2630^2 .

It is a cyclic number.

It is not a de Polignac number, because 78606989 - 2⁴ = 78606973 is a prime.

It is a super-2 number, since 2×78606989² = 12358117439292242, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78606989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78606949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39303494 + 39303495.

It is an arithmetic number, because the mean of its divisors is an integer number (39303495).

Almost surely, 2^78606989 is an apocalyptic number.

It is an amenable number.

78606989 is a deficient number, since it is larger than the sum of its proper divisors (1).

78606989 is an equidigital number, since it uses as much as digits as its factorization.

78606989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1306368, while the sum is 53.

The square root of 78606989 is about 8866.0582560685. The cubic root of 78606989 is about 428.3713204798.

The spelling of 78606989 in words is "seventy-eight million, six hundred six thousand, nine hundred eighty-nine".