21455118 has 20 divisors (see below), whose sum is σ = 48075720. Its totient is φ = 7151652.

The previous prime is 21455117. The next prime is 21455143. The reversal of 21455118 is 81155412.

21455118 is a `hidden beast` number, since 2 + 145 + 511 + 8 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21455091 and 21455100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 66058 + ... + 66381.

It is an arithmetic number, because the mean of its divisors is an integer number (2403786).

Almost surely, 2^21455118 is an apocalyptic number.

21455118 is an abundant number, since it is smaller than the sum of its proper divisors (26620602).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21455118 is a wasteful number, since it uses less digits than its factorization.

21455118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132453 (or 132444 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 21455118 is about 4631.9669687941. The cubic root of 21455118 is about 277.8712634792.

The spelling of 21455118 in words is "twenty-one million, four hundred fifty-five thousand, one hundred eighteen".