1640468687 has 16 divisors (see below), whose sum is σ = 1941152640. Its totient is φ = 1366696800.

The previous prime is 1640468659. The next prime is 1640468699. The reversal of 1640468687 is 7868640461.

It is a cyclic number.

It is not a de Polignac number, because 1640468687 - 2⁶ = 1640468623 is a prime.

It is a super-2 number, since 2×1640468687² = 5382275026055007938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640468287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21389 + ... + 61142.

It is an arithmetic number, because the mean of its divisors is an integer number (121322040).

Almost surely, 2^1640468687 is an apocalyptic number.

1640468687 is a deficient number, since it is larger than the sum of its proper divisors (300683953).

1640468687 is a wasteful number, since it uses less digits than its factorization.

1640468687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82694.

The product of its (nonzero) digits is 1548288, while the sum is 50.

The square root of 1640468687 is about 40502.6997495229. The cubic root of 1640468687 is about 1179.3860367771.

The spelling of 1640468687 in words is "one billion, six hundred forty million, four hundred sixty-eight thousand, six hundred eighty-seven".