2166653339621 has 4 divisors (see below), whose sum is σ = 2166891364032. Its totient is φ = 2166415315212.

The previous prime is 2166653339611. The next prime is 2166653339629. The reversal of 2166653339621 is 1269333566612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166653339621 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 (2166653339629) 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, 118998551 + ... + 119016756.

It is an arithmetic number, because the mean of its divisors is an integer number (541722841008).

Almost surely, 2^{2166653339621} is an apocalyptic number.

It is an amenable number.

2166653339621 is a deficient number, since it is larger than the sum of its proper divisors (238024411).

2166653339621 is an equidigital number, since it uses as much as digits as its factorization.

2166653339621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238024410.

The product of its digits is 6298560, while the sum is 53.

The spelling of 2166653339621 in words is "two trillion, one hundred sixty-six billion, six hundred fifty-three million, three hundred thirty-nine thousand, six hundred twenty-one".