21730196 has 6 divisors (see below), whose sum is σ = 38027850. Its totient is φ = 10865096.

The previous prime is 21730169. The next prime is 21730249. The reversal of 21730196 is 69103712.

It can be written as a sum of positive squares in only one way, i.e., 14167696 + 7562500 = 3764^2 + 2750^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2716271 + ... + 2716278.

It is an arithmetic number, because the mean of its divisors is an integer number (6337975).

Almost surely, 2^21730196 is an apocalyptic number.

It is an amenable number.

21730196 is a deficient number, since it is larger than the sum of its proper divisors (16297654).

21730196 is a wasteful number, since it uses less digits than its factorization.

21730196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5432553 (or 5432551 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21730196 is about 4661.5658313489. The cubic root of 21730196 is about 279.0537616451.

The spelling of 21730196 in words is "twenty-one million, seven hundred thirty thousand, one hundred ninety-six".