78354889 has 2 divisors, whose sum is σ = 78354890. Its totient is φ = 78354888.

The previous prime is 78354851. The next prime is 78354893. The reversal of 78354889 is 98845387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46240000 + 32114889 = 6800^2 + 5667^2 .

It is a cyclic number.

It is not a de Polignac number, because 78354889 - 2⁷ = 78354761 is a prime.

It is a super-2 number, since 2×78354889² = 12278977260404642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78354389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39177444 + 39177445.

It is an arithmetic number, because the mean of its divisors is an integer number (39177445).

Almost surely, 2^78354889 is an apocalyptic number.

It is an amenable number.

78354889 is a deficient number, since it is larger than the sum of its proper divisors (1).

78354889 is an equidigital number, since it uses as much as digits as its factorization.

78354889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1935360, while the sum is 52.

The square root of 78354889 is about 8851.8296978647. The cubic root of 78354889 is about 427.9128876921.

The spelling of 78354889 in words is "seventy-eight million, three hundred fifty-four thousand, eight hundred eighty-nine".