21194220 has 24 divisors (see below), whose sum is σ = 59343984. Its totient is φ = 5651776.

The previous prime is 21194219. The next prime is 21194221. The reversal of 21194220 is 2249112.

It is an interprime number because it is at equal distance from previous prime (21194219) and next prime (21194221).

It is a super-2 number, since 2×21194220² = 898389922816800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21194221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 176559 + ... + 176678.

It is an arithmetic number, because the mean of its divisors is an integer number (2472666).

Almost surely, 2^21194220 is an apocalyptic number.

21194220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21194220 is an abundant number, since it is smaller than the sum of its proper divisors (38149764).

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

21194220 is a wasteful number, since it uses less digits than its factorization.

21194220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353249 (or 353247 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21194220 is about 4603.7180626098. The cubic root of 21194220 is about 276.7403458547.

The spelling of 21194220 in words is "twenty-one million, one hundred ninety-four thousand, two hundred twenty".