21129366 has 8 divisors (see below), whose sum is σ = 42258744. Its totient is φ = 7043120.

The previous prime is 21129359. The next prime is 21129377. The reversal of 21129366 is 66392112.

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

21129366 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1760775 + ... + 1760786.

It is an arithmetic number, because the mean of its divisors is an integer number (5282343).

Almost surely, 2^21129366 is an apocalyptic number.

21129366 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.

21129366 is a wasteful number, since it uses less digits than its factorization.

21129366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3521566.

The product of its digits is 3888, while the sum is 30.

The square root of 21129366 is about 4596.6690113603. The cubic root of 21129366 is about 276.4577836568.

The spelling of 21129366 in words is "twenty-one million, one hundred twenty-nine thousand, three hundred sixty-six".