1640168990 has 32 divisors (see below), whose sum is σ = 2976130080. Its totient is φ = 650795904.

The previous prime is 1640168989. The next prime is 1640169029. The reversal of 1640168990 is 998610461.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 701864 + ... + 704196.

It is an arithmetic number, because the mean of its divisors is an integer number (93004065).

Almost surely, 2^1640168990 is an apocalyptic number.

1640168990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1640168990 is a deficient number, since it is larger than the sum of its proper divisors (1335961090).

1640168990 is a wasteful number, since it uses less digits than its factorization.

1640168990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2876.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 1640168990 is about 40498.9998641942. Note that the first 3 decimals coincide. The cubic root of 1640168990 is about 1179.3142117785.

The spelling of 1640168990 in words is "one billion, six hundred forty million, one hundred sixty-eight thousand, nine hundred ninety".