21428194 has 24 divisors (see below), whose sum is σ = 34526448. Its totient is φ = 9971520.

The previous prime is 21428191. The next prime is 21428207. The reversal of 21428194 is 49182412.

It is not an unprimeable number, because it can be changed into a prime (21428191) 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, 75577 + ... + 75859.

It is an arithmetic number, because the mean of its divisors is an integer number (1438602).

Almost surely, 2^21428194 is an apocalyptic number.

21428194 is a deficient number, since it is larger than the sum of its proper divisors (13098254).

21428194 is a wasteful number, since it uses less digits than its factorization.

21428194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 433 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 21428194 is about 4629.0597317382. The cubic root of 21428194 is about 277.7549813944.

The spelling of 21428194 in words is "twenty-one million, four hundred twenty-eight thousand, one hundred ninety-four".