978491 has 2 divisors, whose sum is σ = 978492. Its totient is φ = 978490.

The previous prime is 978479. The next prime is 978511. The reversal of 978491 is 194879.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 978491 - 2⁶ = 978427 is a prime.

It is not a weakly prime, because it can be changed into another prime (978091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489245 + 489246.

It is an arithmetic number, because the mean of its divisors is an integer number (489246).

2⁹⁷⁸⁴⁹¹ is an apocalyptic number.

978491 is a deficient number, since it is larger than the sum of its proper divisors (1).

978491 is an equidigital number, since it uses as much as digits as its factorization.

978491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 978491 is about 989.1870399475. The cubic root of 978491 is about 99.2778306013.

The spelling of 978491 in words is "nine hundred seventy-eight thousand, four hundred ninety-one".