21894097 has 2 divisors, whose sum is σ = 21894098. Its totient is φ = 21894096.

The previous prime is 21894083. The next prime is 21894109. The reversal of 21894097 is 79049812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21538881 + 355216 = 4641^2 + 596^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21894097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21894017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10947048 + 10947049.

It is an arithmetic number, because the mean of its divisors is an integer number (10947049).

Almost surely, 2^21894097 is an apocalyptic number.

It is an amenable number.

21894097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21894097 is an equidigital number, since it uses as much as digits as its factorization.

21894097 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 21894097 is about 4679.1128432642. The cubic root of 21894097 is about 279.7535970018.

The spelling of 21894097 in words is "twenty-one million, eight hundred ninety-four thousand, ninety-seven".