1640450373 has 4 divisors (see below), whose sum is σ = 2187267168. Its totient is φ = 1093633580.

The previous prime is 1640450363. The next prime is 1640450381. The reversal of 1640450373 is 3730540461.

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 a cyclic number.

It is not a de Polignac number, because 1640450373 - 2⁵ = 1640450341 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640450363) 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, 273408393 + ... + 273408398.

It is an arithmetic number, because the mean of its divisors is an integer number (546816792).

Almost surely, 2^1640450373 is an apocalyptic number.

It is an amenable number.

1640450373 is a deficient number, since it is larger than the sum of its proper divisors (546816795).

1640450373 is an equidigital number, since it uses as much as digits as its factorization.

1640450373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546816794.

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 1640450373 is about 40502.4736651973. The cubic root of 1640450373 is about 1179.3816479183.

The spelling of 1640450373 in words is "one billion, six hundred forty million, four hundred fifty thousand, three hundred seventy-three".