21998222 has 8 divisors (see below), whose sum is σ = 33802272. Its totient is φ = 10730800.

The previous prime is 21998203. The next prime is 21998231. The reversal of 21998222 is 22289912.

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

It is a super-2 number, since 2×21998222² = 967843542322568, which contains 22 as substring.

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, 134054 + ... + 134217.

It is an arithmetic number, because the mean of its divisors is an integer number (4225284).

Almost surely, 2^21998222 is an apocalyptic number.

21998222 is a deficient number, since it is larger than the sum of its proper divisors (11804050).

21998222 is a wasteful number, since it uses less digits than its factorization.

21998222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268314.

The product of its digits is 10368, while the sum is 35.

The square root of 21998222 is about 4690.2262205570. The cubic root of 21998222 is about 280.1963843380.

The spelling of 21998222 in words is "twenty-one million, nine hundred ninety-eight thousand, two hundred twenty-two".