646061131998 has 56 divisors (see below), whose sum is σ = 1453644417528. Its totient is φ = 215352647784.

The previous prime is 646061131981. The next prime is 646061132009. The reversal of 646061131998 is 899131160646.

It is a happy number.

646061131998 is a `hidden beast` number, since 6 + 4 + 6 + 0 + 611 + 3 + 19 + 9 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 3087340 + ... + 3289952.

Almost surely, 2^646061131998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646061131998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (726822208764).

646061131998 is an abundant number, since it is smaller than the sum of its proper divisors (807583285530).

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

646061131998 is an frugal number, since it uses more digits than its factorization.

646061131998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202654 (or 202618 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 646061131998 in words is "six hundred forty-six billion, sixty-one million, one hundred thirty-one thousand, nine hundred ninety-eight".