1639263945 has 32 divisors (see below), whose sum is σ = 2870492544. Its totient is φ = 792230400.

The previous prime is 1639263943. The next prime is 1639263953. The reversal of 1639263945 is 5493629361.

It is not a de Polignac number, because 1639263945 - 2¹ = 1639263943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1639263894 and 1639263903.

It is not an unprimeable number, because it can be changed into a prime (1639263943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35775 + ... + 67515.

It is an arithmetic number, because the mean of its divisors is an integer number (89702892).

Almost surely, 2^1639263945 is an apocalyptic number.

1639263945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1639263945 is a deficient number, since it is larger than the sum of its proper divisors (1231228599).

1639263945 is a wasteful number, since it uses less digits than its factorization.

1639263945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32073.

The product of its digits is 1049760, while the sum is 48.

The square root of 1639263945 is about 40487.8246513690. The cubic root of 1639263945 is about 1179.0972567339.

The spelling of 1639263945 in words is "one billion, six hundred thirty-nine million, two hundred sixty-three thousand, nine hundred forty-five".