640982 has 8 divisors (see below), whose sum is σ = 979776. Its totient is φ = 314392.

The previous prime is 640973. The next prime is 640993. The reversal of 640982 is 289046.

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

It is a congruent number.

It is an unprimeable number.

640982 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2918 + ... + 3129.

It is an arithmetic number, because the mean of its divisors is an integer number (122472).

2⁶⁴⁰⁹⁸² is an apocalyptic number.

640982 is a deficient number, since it is larger than the sum of its proper divisors (338794).

640982 is a wasteful number, since it uses less digits than its factorization.

640982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6102.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 640982 is about 800.6135147498. The cubic root of 640982 is about 86.2214412204.

The spelling of 640982 in words is "six hundred forty thousand, nine hundred eighty-two".