641979000 has 512 divisors, whose sum is σ = 2515968000. Its totient is φ = 150336000.

The previous prime is 641978999. The next prime is 641979001. The reversal of 641979000 is 979146.

641979000 is a `hidden beast` number, since 641 + 9 + 7 + 9 + 0 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (641978999) and next prime (641979001).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641979001) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10880971 + ... + 10881029.

It is an arithmetic number, because the mean of its divisors is an integer number (4914000).

Almost surely, 2^641979000 is an apocalyptic number.

641979000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641979000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1257984000).

641979000 is an abundant number, since it is smaller than the sum of its proper divisors (1873989000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641979000 is a wasteful number, since it uses less digits than its factorization.

641979000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 641979000 is about 25337.3045133061. The cubic root of 641979000 is about 862.6612175006.

The spelling of 641979000 in words is "six hundred forty-one million, nine hundred seventy-nine thousand".