3564521621 has 4 divisors (see below), whose sum is σ = 3574735500. Its totient is φ = 3554307744.

The previous prime is 3564521579. The next prime is 3564521683. The reversal of 3564521621 is 1261254653.

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 1458170596 + 2106351025 = 38186^2 + 45895^2 .

It is a cyclic number.

It is not a de Polignac number, because 3564521621 - 2²⁶ = 3497412757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3564521021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5106416 + ... + 5107113.

It is an arithmetic number, because the mean of its divisors is an integer number (893683875).

Almost surely, 2^3564521621 is an apocalyptic number.

It is an amenable number.

3564521621 is a deficient number, since it is larger than the sum of its proper divisors (10213879).

3564521621 is a wasteful number, since it uses less digits than its factorization.

3564521621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10213878.

The product of its digits is 43200, while the sum is 35.

The square root of 3564521621 is about 59703.6148068105. The cubic root of 3564521621 is about 1527.5675276920.

The spelling of 3564521621 in words is "three billion, five hundred sixty-four million, five hundred twenty-one thousand, six hundred twenty-one".