21996853 has 2 divisors, whose sum is σ = 21996854. Its totient is φ = 21996852.

The previous prime is 21996841. The next prime is 21996859. The reversal of 21996853 is 35869912.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21511044 + 485809 = 4638^2 + 697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21996853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21996859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998426 + 10998427.

It is an arithmetic number, because the mean of its divisors is an integer number (10998427).

Almost surely, 2^21996853 is an apocalyptic number.

It is an amenable number.

21996853 is a deficient number, since it is larger than the sum of its proper divisors (1).

21996853 is an equidigital number, since it uses as much as digits as its factorization.

21996853 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 43.

The square root of 21996853 is about 4690.0802764985. The cubic root of 21996853 is about 280.1905717954.

The spelling of 21996853 in words is "twenty-one million, nine hundred ninety-six thousand, eight hundred fifty-three".