18055961 has 24 divisors (see below), whose sum is σ = 23173920. Its totient is φ = 13910400.

The previous prime is 18055927. The next prime is 18055993. The reversal of 18055961 is 16955081.

It is not a de Polignac number, because 18055961 - 2¹⁴ = 18039577 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18055901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74801 + ... + 75041.

It is an arithmetic number, because the mean of its divisors is an integer number (965580).

Almost surely, 2^18055961 is an apocalyptic number.

18055961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18055961 is a deficient number, since it is larger than the sum of its proper divisors (5117959).

18055961 is a wasteful number, since it uses less digits than its factorization.

18055961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 18055961 is about 4249.2306362446. The cubic root of 18055961 is about 262.3454497652.

The spelling of 18055961 in words is "eighteen million, fifty-five thousand, nine hundred sixty-one".