3969619645 has 4 divisors (see below), whose sum is σ = 4763543580. Its totient is φ = 3175695712.

The previous prime is 3969619637. The next prime is 3969619679. The reversal of 3969619645 is 5469169693.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2929299129 + 1040320516 = 54123^2 + 32254^2 .

It is a cyclic number.

It is not a de Polignac number, because 3969619645 - 2³ = 3969619637 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 3969619645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396961960 + ... + 396961969.

It is an arithmetic number, because the mean of its divisors is an integer number (1190885895).

Almost surely, 2^3969619645 is an apocalyptic number.

It is an amenable number.

3969619645 is a deficient number, since it is larger than the sum of its proper divisors (793923935).

3969619645 is an equidigital number, since it uses as much as digits as its factorization.

3969619645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793923934.

The product of its digits is 9447840, while the sum is 58.

The square root of 3969619645 is about 63004.9176255314. The cubic root of 3969619645 is about 1583.3720171035.

The spelling of 3969619645 in words is "three billion, nine hundred sixty-nine million, six hundred nineteen thousand, six hundred forty-five".