2155223162661 has 4 divisors (see below), whose sum is σ = 2873630883552. Its totient is φ = 1436815441772.

The previous prime is 2155223162633. The next prime is 2155223162669. The reversal of 2155223162661 is 1662613225512.

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 2155223162661 - 2¹⁷ = 2155223031589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155223162669) 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, 359203860441 + ... + 359203860446.

It is an arithmetic number, because the mean of its divisors is an integer number (718407720888).

Almost surely, 2^{2155223162661} is an apocalyptic number.

It is an amenable number.

2155223162661 is a deficient number, since it is larger than the sum of its proper divisors (718407720891).

2155223162661 is an equidigital number, since it uses as much as digits as its factorization.

2155223162661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718407720890.

The product of its digits is 259200, while the sum is 42.

The spelling of 2155223162661 in words is "two trillion, one hundred fifty-five billion, two hundred twenty-three million, one hundred sixty-two thousand, six hundred sixty-one".