78497989 has 2 divisors, whose sum is σ = 78497990. Its totient is φ = 78497988.

The previous prime is 78497977. The next prime is 78498001. The reversal of 78497989 is 98979487.

It is a balanced prime because it is at equal distance from previous prime (78497977) and next prime (78498001).

It can be written as a sum of positive squares in only one way, i.e., 78021889 + 476100 = 8833^2 + 690^2 .

It is a cyclic number.

It is not a de Polignac number, because 78497989 - 2⁵ = 78497957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78497389) 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 as a sum of consecutive naturals, namely, 39248994 + 39248995.

It is an arithmetic number, because the mean of its divisors is an integer number (39248995).

Almost surely, 2^78497989 is an apocalyptic number.

It is an amenable number.

78497989 is a deficient number, since it is larger than the sum of its proper divisors (1).

78497989 is an equidigital number, since it uses as much as digits as its factorization.

78497989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9144576, while the sum is 61.

The square root of 78497989 is about 8859.9090853123. The cubic root of 78497989 is about 428.1732292196.

The spelling of 78497989 in words is "seventy-eight million, four hundred ninety-seven thousand, nine hundred eighty-nine".