21722093 has 2 divisors, whose sum is σ = 21722094. Its totient is φ = 21722092.

The previous prime is 21722081. The next prime is 21722101. The reversal of 21722093 is 39022712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20775364 + 946729 = 4558^2 + 973^2 .

It is a cyclic number.

It is not a de Polignac number, because 21722093 - 2²⁰ = 20673517 is a prime.

It is a super-3 number, since 3×21722093³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21722693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10861046 + 10861047.

It is an arithmetic number, because the mean of its divisors is an integer number (10861047).

Almost surely, 2^21722093 is an apocalyptic number.

It is an amenable number.

21722093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21722093 is an equidigital number, since it uses as much as digits as its factorization.

21722093 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21722093 is about 4660.6966217509. The cubic root of 21722093 is about 279.0190717640.

The spelling of 21722093 in words is "twenty-one million, seven hundred twenty-two thousand, ninety-three".