2161503115621 has 4 divisors (see below), whose sum is σ = 2161512057600. Its totient is φ = 2161494173644.

The previous prime is 2161503115619. The next prime is 2161503115753. The reversal of 2161503115621 is 1265113051612.

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 not a de Polignac number, because 2161503115621 - 2¹ = 2161503115619 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 (2161503115601) 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, 4098031 + ... + 4595308.

It is an arithmetic number, because the mean of its divisors is an integer number (540378014400).

Almost surely, 2^{2161503115621} is an apocalyptic number.

It is an amenable number.

2161503115621 is a deficient number, since it is larger than the sum of its proper divisors (8941979).

2161503115621 is an equidigital number, since it uses as much as digits as its factorization.

2161503115621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8941978.

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 2161503115621 in words is "two trillion, one hundred sixty-one billion, five hundred three million, one hundred fifteen thousand, six hundred twenty-one".