21732197 has 2 divisors, whose sum is σ = 21732198. Its totient is φ = 21732196.

The previous prime is 21732169. The next prime is 21732203. The reversal of 21732197 is 79123712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21215236 + 516961 = 4606^2 + 719^2 .

It is a cyclic number.

It is not a de Polignac number, because 21732197 - 2¹² = 21728101 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21732497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10866098 + 10866099.

It is an arithmetic number, because the mean of its divisors is an integer number (10866099).

Almost surely, 2^21732197 is an apocalyptic number.

It is an amenable number.

21732197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21732197 is an equidigital number, since it uses as much as digits as its factorization.

21732197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292, while the sum is 32.

The square root of 21732197 is about 4661.7804538609. The cubic root of 21732197 is about 279.0623268300.

The spelling of 21732197 in words is "twenty-one million, seven hundred thirty-two thousand, one hundred ninety-seven".