21155214 has 8 divisors (see below), whose sum is σ = 42310440. Its totient is φ = 7051736.

The previous prime is 21155207. The next prime is 21155219. The reversal of 21155214 is 41255112.

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

21155214 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155219) 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, 1762929 + ... + 1762940.

It is an arithmetic number, because the mean of its divisors is an integer number (5288805).

Almost surely, 2^21155214 is an apocalyptic number.

21155214 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.

21155214 is a wasteful number, since it uses less digits than its factorization.

21155214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3525874.

The product of its digits is 400, while the sum is 21.

The square root of 21155214 is about 4599.4797531895. The cubic root of 21155214 is about 276.5704699353.

The spelling of 21155214 in words is "twenty-one million, one hundred fifty-five thousand, two hundred fourteen".