1640053994 has 16 divisors (see below), whose sum is σ = 2547001800. Its totient is φ = 791099904.

The previous prime is 1640053993. The next prime is 1640054041. The reversal of 1640053994 is 4993500461.

It can be written as a sum of positive squares in 4 ways, for example, as 1393155625 + 246898369 = 37325^2 + 15713^2 .

It is not an unprimeable number, because it can be changed into a prime (1640053993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63794 + ... + 85730.

Almost surely, 2^1640053994 is an apocalyptic number.

1640053994 is a deficient number, since it is larger than the sum of its proper divisors (906947806).

1640053994 is a wasteful number, since it uses less digits than its factorization.

1640053994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23257.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 1640053994 is about 40497.5801005443. The cubic root of 1640053994 is about 1179.2866496619.

The spelling of 1640053994 in words is "one billion, six hundred forty million, fifty-three thousand, nine hundred ninety-four".