18381051 has 12 divisors (see below), whose sum is σ = 28592928. Its totient is φ = 11311344.

The previous prime is 18381049. The next prime is 18381059. The reversal of 18381051 is 15018381.

It is not a de Polignac number, because 18381051 - 2¹ = 18381049 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18381059) 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, 78435 + ... + 78668.

It is an arithmetic number, because the mean of its divisors is an integer number (2382744).

Almost surely, 2^18381051 is an apocalyptic number.

18381051 is a deficient number, since it is larger than the sum of its proper divisors (10211877).

18381051 is a wasteful number, since it uses less digits than its factorization.

18381051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157122 (or 157119 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 18381051 is about 4287.3127947468. The cubic root of 18381051 is about 263.9105671589.

The spelling of 18381051 in words is "eighteen million, three hundred eighty-one thousand, fifty-one".