2188337811661 has 4 divisors (see below), whose sum is σ = 2220999570112. Its totient is φ = 2155676053212.

The previous prime is 2188337811617. The next prime is 2188337811799. The reversal of 2188337811661 is 1661187338812.

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 2188337811661 - 2¹³ = 2188337803469 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 (2188337811061) 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, 16330879125 + ... + 16330879258.

It is an arithmetic number, because the mean of its divisors is an integer number (555249892528).

Almost surely, 2^{2188337811661} is an apocalyptic number.

It is an amenable number.

2188337811661 is a deficient number, since it is larger than the sum of its proper divisors (32661758451).

2188337811661 is an equidigital number, since it uses as much as digits as its factorization.

2188337811661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32661758450.

The product of its digits is 2322432, while the sum is 55.

The spelling of 2188337811661 in words is "two trillion, one hundred eighty-eight billion, three hundred thirty-seven million, eight hundred eleven thousand, six hundred sixty-one".