641998 has 12 divisors (see below), whose sum is σ = 1120392. Its totient is φ = 275100.

The previous prime is 641981. The next prime is 642011. The reversal of 641998 is 899146.

It is a super-2 number, since 2×641998² = 824322864008, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3178 + ... + 3373.

It is an arithmetic number, because the mean of its divisors is an integer number (93366).

2⁶⁴¹⁹⁹⁸ is an apocalyptic number.

641998 is a deficient number, since it is larger than the sum of its proper divisors (478394).

641998 is a wasteful number, since it uses less digits than its factorization.

641998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6567 (or 6560 counting only the distinct ones).

The product of its digits is 15552, while the sum is 37.

The square root of 641998 is about 801.2477769080. The cubic root of 641998 is about 86.2669727852.

The spelling of 641998 in words is "six hundred forty-one thousand, nine hundred ninety-eight".