2155561623 has 12 divisors (see below), whose sum is σ = 3114037680. Its totient is φ = 1436834016.

The previous prime is 2155561621. The next prime is 2155561627. The reversal of 2155561623 is 3261655512.

2155561623 is a `hidden beast` number, since 2 + 15 + 5 + 5 + 616 + 23 = 666.

It is not a de Polignac number, because 2155561623 - 2¹ = 2155561621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155561621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74163 + ... + 99051.

It is an arithmetic number, because the mean of its divisors is an integer number (259503140).

Almost surely, 2^2155561623 is an apocalyptic number.

2155561623 is a deficient number, since it is larger than the sum of its proper divisors (958476057).

2155561623 is a wasteful number, since it uses less digits than its factorization.

2155561623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34518 (or 34515 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 2155561623 is about 46428.0262664697. The cubic root of 2155561623 is about 1291.7748186172.

The spelling of 2155561623 in words is "two billion, one hundred fifty-five million, five hundred sixty-one thousand, six hundred twenty-three".