978999 has 8 divisors (see below), whose sum is σ = 1491840. Its totient is φ = 559416.

The previous prime is 978997. The next prime is 979001. The reversal of 978999 is 999879.

It is an interprime number because it is at equal distance from previous prime (978997) and next prime (979001).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 978999 - 2¹ = 978997 is a prime.

978999 is a modest number, since divided by 999 gives 978 as remainder.

978999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23289 + ... + 23330.

It is an arithmetic number, because the mean of its divisors is an integer number (186480).

2⁹⁷⁸⁹⁹⁹ is an apocalyptic number.

978999 is a deficient number, since it is larger than the sum of its proper divisors (512841).

978999 is a wasteful number, since it uses less digits than its factorization.

978999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46629.

The product of its digits is 367416, while the sum is 51.

The square root of 978999 is about 989.4437831428. The cubic root of 978999 is about 99.2950082121.

The spelling of 978999 in words is "nine hundred seventy-eight thousand, nine hundred ninety-nine".