1640311866 has 48 divisors (see below), whose sum is σ = 3679603200. Its totient is φ = 527554080.

The previous prime is 1640311853. The next prime is 1640311873. The reversal of 1640311866 is 6681130461.

1640311866 is a `hidden beast` number, since 1 + 640 + 3 + 1 + 1 + 8 + 6 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1640311866.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 190531 + ... + 198953.

It is an arithmetic number, because the mean of its divisors is an integer number (76658400).

Almost surely, 2^1640311866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640311866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1839801600).

1640311866 is an abundant number, since it is smaller than the sum of its proper divisors (2039291334).

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

1640311866 is a wasteful number, since it uses less digits than its factorization.

1640311866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8811 (or 8808 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1640311866 is about 40500.7637705760. The cubic root of 1640311866 is about 1179.3484543486.

The spelling of 1640311866 in words is "one billion, six hundred forty million, three hundred eleven thousand, eight hundred sixty-six".