78455491 has 2 divisors, whose sum is σ = 78455492. Its totient is φ = 78455490.

The previous prime is 78455483. The next prime is 78455519. The reversal of 78455491 is 19455487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78455491 - 2³ = 78455483 is a prime.

It is not a weakly prime, because it can be changed into another prime (78455401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39227745 + 39227746.

It is an arithmetic number, because the mean of its divisors is an integer number (39227746).

Almost surely, 2^78455491 is an apocalyptic number.

78455491 is a deficient number, since it is larger than the sum of its proper divisors (1).

78455491 is an equidigital number, since it uses as much as digits as its factorization.

78455491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 43.

The square root of 78455491 is about 8857.5104290088. The cubic root of 78455491 is about 428.0959457506.

The spelling of 78455491 in words is "seventy-eight million, four hundred fifty-five thousand, four hundred ninety-one".