1640043453 has 4 divisors (see below), whose sum is σ = 2186724608. Its totient is φ = 1093362300.

The previous prime is 1640043443. The next prime is 1640043479. The reversal of 1640043453 is 3543400461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1640043453 - 2¹⁰ = 1640042429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1640043453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640043403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273340573 + ... + 273340578.

It is an arithmetic number, because the mean of its divisors is an integer number (546681152).

Almost surely, 2^1640043453 is an apocalyptic number.

It is an amenable number.

1640043453 is a deficient number, since it is larger than the sum of its proper divisors (546681155).

1640043453 is an equidigital number, since it uses as much as digits as its factorization.

1640043453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546681154.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 1640043453 is about 40497.4499567565. The cubic root of 1640043453 is about 1179.2841231420.

The spelling of 1640043453 in words is "one billion, six hundred forty million, forty-three thousand, four hundred fifty-three".