21053118 has 8 divisors (see below), whose sum is σ = 42106248. Its totient is φ = 7017704.

The previous prime is 21053117. The next prime is 21053129. The reversal of 21053118 is 81135012.

It is a sphenic number, since it is the product of 3 distinct primes.

21053118 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21053094 and 21053103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053117) 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, 1754421 + ... + 1754432.

It is an arithmetic number, because the mean of its divisors is an integer number (5263281).

Almost surely, 2^21053118 is an apocalyptic number.

21053118 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21053118 is a wasteful number, since it uses less digits than its factorization.

21053118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3508858.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 21053118 is about 4588.3676836104. The cubic root of 21053118 is about 276.1248385054.

The spelling of 21053118 in words is "twenty-one million, fifty-three thousand, one hundred eighteen".