1651599965 has 16 divisors (see below), whose sum is σ = 1998744240. Its totient is φ = 1310100480.

The previous prime is 1651599931. The next prime is 1651600019. The reversal of 1651599965 is 5699951561.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 20894041 + 1630705924 = 4571^2 + 40382^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1651599965 is a prime.

It is a Smith number, since the sum of its digits (56) 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 1651599965.

It is a congruent number.

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, 422741 + ... + 426629.

It is an arithmetic number, because the mean of its divisors is an integer number (124921515).

Almost surely, 2^1651599965 is an apocalyptic number.

It is an amenable number.

1651599965 is a deficient number, since it is larger than the sum of its proper divisors (347144275).

1651599965 is a wasteful number, since it uses less digits than its factorization.

1651599965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4592.

The product of its digits is 3280500, while the sum is 56.

The square root of 1651599965 is about 40639.8814589807. The cubic root of 1651599965 is about 1182.0475712905.

The spelling of 1651599965 in words is "one billion, six hundred fifty-one million, five hundred ninety-nine thousand, nine hundred sixty-five".