978643 has 2 divisors, whose sum is σ = 978644. Its totient is φ = 978642.

The previous prime is 978619. The next prime is 978647. The reversal of 978643 is 346879.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 978643 - 2⁵ = 978611 is a prime.

It is a d-powerful number, because it can be written as 9⁵ + 7⁷ + 6⁶ + 8⁵ + 4⁷ + 3⁵ .

It is equal to p₇₆₉₇₈ and since 978643 and 76978 have the same sum of digits, it is a Honaker prime.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (978647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489321 + 489322.

It is an arithmetic number, because the mean of its divisors is an integer number (489322).

2⁹⁷⁸⁶⁴³ is an apocalyptic number.

978643 is a deficient number, since it is larger than the sum of its proper divisors (1).

978643 is an equidigital number, since it uses as much as digits as its factorization.

978643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 978643 is about 989.2638677320. The cubic root of 978643 is about 99.2829709821.

The spelling of 978643 in words is "nine hundred seventy-eight thousand, six hundred forty-three".