3621660821421 has 16 divisors (see below), whose sum is σ = 4929834484800. Its totient is φ = 2364282318848.

The previous prime is 3621660821413. The next prime is 3621660821453. The reversal of 3621660821421 is 1241280661263.

It is a cyclic number.

It is not a de Polignac number, because 3621660821421 - 2³ = 3621660821413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3621660821221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39762606 + ... + 39853583.

It is an arithmetic number, because the mean of its divisors is an integer number (308114655300).

Almost surely, 2^{3621660821421} is an apocalyptic number.

It is an amenable number.

3621660821421 is a deficient number, since it is larger than the sum of its proper divisors (1308173663379).

3621660821421 is a wasteful number, since it uses less digits than its factorization.

3621660821421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79616508.

The product of its (nonzero) digits is 165888, while the sum is 42.

The spelling of 3621660821421 in words is "three trillion, six hundred twenty-one billion, six hundred sixty million, eight hundred twenty-one thousand, four hundred twenty-one".