651998 has 4 divisors (see below), whose sum is σ = 978000. Its totient is φ = 325998.

The previous prime is 651997. The next prime is 652019. The reversal of 651998 is 899156.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162998 + ... + 163001.

It is an arithmetic number, because the mean of its divisors is an integer number (244500).

2⁶⁵¹⁹⁹⁸ is an apocalyptic number.

651998 is a deficient number, since it is larger than the sum of its proper divisors (326002).

651998 is a wasteful number, since it uses less digits than its factorization.

651998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326001.

The product of its digits is 19440, while the sum is 38.

The square root of 651998 is about 807.4639310830. The cubic root of 651998 is about 86.7125759395.

The spelling of 651998 in words is "six hundred fifty-one thousand, nine hundred ninety-eight".