1640861898 has 24 divisors (see below), whose sum is σ = 3553584768. Its totient is φ = 504880272.

The previous prime is 1640861881. The next prime is 1640861933. The reversal of 1640861898 is 8981680461.

It is a super-3 number, since 3×1640861898³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1640861898.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 808090 + ... + 810117.

It is an arithmetic number, because the mean of its divisors is an integer number (148066032).

Almost surely, 2^1640861898 is an apocalyptic number.

1640861898 is an abundant number, since it is smaller than the sum of its proper divisors (1912722870).

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

1640861898 is a wasteful number, since it uses less digits than its factorization.

1640861898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618238 (or 1618225 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 51.

The square root of 1640861898 is about 40507.5535918920. The cubic root of 1640861898 is about 1179.4802599543.

The spelling of 1640861898 in words is "one billion, six hundred forty million, eight hundred sixty-one thousand, eight hundred ninety-eight".