1640305345 has 24 divisors (see below), whose sum is σ = 2277326016. Its totient is φ = 1111065888.

The previous prime is 1640305339. The next prime is 1640305351. The reversal of 1640305345 is 5435030461.

It is an interprime number because it is at equal distance from previous prime (1640305339) and next prime (1640305351).

It is not a de Polignac number, because 1640305345 - 2⁹ = 1640304833 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 237714 + ... + 244516.

It is an arithmetic number, because the mean of its divisors is an integer number (94888584).

Almost surely, 2^1640305345 is an apocalyptic number.

It is an amenable number.

1640305345 is a deficient number, since it is larger than the sum of its proper divisors (637020671).

1640305345 is an frugal number, since it uses more digits than its factorization.

1640305345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6981 (or 6898 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 1640305345 is about 40500.6832658413. The cubic root of 1640305345 is about 1179.3468915276.

The spelling of 1640305345 in words is "one billion, six hundred forty million, three hundred five thousand, three hundred forty-five".