1639706345 has 16 divisors (see below), whose sum is σ = 1976403648. Its totient is φ = 1305944640.

The previous prime is 1639706339. The next prime is 1639706353. The reversal of 1639706345 is 5436079361.

It is a happy number.

It is not a de Polignac number, because 1639706345 - 2⁴ = 1639706329 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1639706296 and 1639706305.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1807382 + ... + 1808288.

It is an arithmetic number, because the mean of its divisors is an integer number (123525228).

Almost surely, 2^1639706345 is an apocalyptic number.

It is an amenable number.

1639706345 is a deficient number, since it is larger than the sum of its proper divisors (336697303).

1639706345 is an equidigital number, since it uses as much as digits as its factorization.

1639706345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120.

The product of its (nonzero) digits is 408240, while the sum is 44.

The square root of 1639706345 is about 40493.2876536346. The cubic root of 1639706345 is about 1179.2033176908.

The spelling of 1639706345 in words is "one billion, six hundred thirty-nine million, seven hundred six thousand, three hundred forty-five".