21948893 has 2 divisors, whose sum is σ = 21948894. Its totient is φ = 21948892.

The previous prime is 21948863. The next prime is 21948929. The reversal of 21948893 is 39884912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21279769 + 669124 = 4613^2 + 818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21948893 - 2⁸ = 21948637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21948863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10974446 + 10974447.

It is an arithmetic number, because the mean of its divisors is an integer number (10974447).

Almost surely, 2^21948893 is an apocalyptic number.

It is an amenable number.

21948893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21948893 is an equidigital number, since it uses as much as digits as its factorization.

21948893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 44.

The square root of 21948893 is about 4684.9645676355. The cubic root of 21948893 is about 279.9867893427.

The spelling of 21948893 in words is "twenty-one million, nine hundred forty-eight thousand, eight hundred ninety-three".