1640459643 has 16 divisors (see below), whose sum is σ = 2258958336. Its totient is φ = 1057835520.

The previous prime is 1640459633. The next prime is 1640459669. The reversal of 1640459643 is 3469540461.

It is a happy number.

It is not a de Polignac number, because 1640459643 - 2⁴ = 1640459627 is a prime.

It is a super-2 number, since 2×1640459643² = 5382215680623374898, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1640459595 and 1640459604.

It is not an unprimeable number, because it can be changed into a prime (1640459633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 288930 + ... + 294552.

It is an arithmetic number, because the mean of its divisors is an integer number (141184896).

Almost surely, 2^1640459643 is an apocalyptic number.

1640459643 is a deficient number, since it is larger than the sum of its proper divisors (618498693).

1640459643 is a wasteful number, since it uses less digits than its factorization.

1640459643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8794.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 1640459643 is about 40502.5881024904. The cubic root of 1640459643 is about 1179.3838694317.

The spelling of 1640459643 in words is "one billion, six hundred forty million, four hundred fifty-nine thousand, six hundred forty-three".