3645973621561 has 8 divisors (see below), whose sum is σ = 3648463168320. Its totient is φ = 3643484306448.

The previous prime is 3645973621457. The next prime is 3645973621601. The reversal of 3645973621561 is 1651263795463.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3645973621561 - 2²³ = 3645965232953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3645973621496 and 3645973621505.

It is not an unprimeable number, because it can be changed into a prime (3645973621361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41384220 + ... + 41472226.

It is an arithmetic number, because the mean of its divisors is an integer number (456057896040).

Almost surely, 2^{3645973621561} is an apocalyptic number.

It is an amenable number.

3645973621561 is a deficient number, since it is larger than the sum of its proper divisors (2489546759).

3645973621561 is a wasteful number, since it uses less digits than its factorization.

3645973621561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115823.

The product of its digits is 24494400, while the sum is 58.

The spelling of 3645973621561 in words is "three trillion, six hundred forty-five billion, nine hundred seventy-three million, six hundred twenty-one thousand, five hundred sixty-one".