1640254091 has 8 divisors (see below), whose sum is σ = 1892776704. Its totient is φ = 1392281640.

The previous prime is 1640253997. The next prime is 1640254093. The reversal of 1640254091 is 1904520461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1640254091 - 2¹⁰ = 1640253067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640254093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1136765 + ... + 1138206.

It is an arithmetic number, because the mean of its divisors is an integer number (236597088).

Almost surely, 2^1640254091 is an apocalyptic number.

1640254091 is a deficient number, since it is larger than the sum of its proper divisors (252522613).

1640254091 is a wasteful number, since it uses less digits than its factorization.

1640254091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2275081.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1640254091 is about 40500.0505061413. The cubic root of 1640254091 is about 1179.3346078644.

The spelling of 1640254091 in words is "one billion, six hundred forty million, two hundred fifty-four thousand, ninety-one".