21634453 has 2 divisors, whose sum is σ = 21634454. Its totient is φ = 21634452.

The previous prime is 21634451. The next prime is 21634537. The reversal of 21634453 is 35443612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14569489 + 7064964 = 3817^2 + 2658^2 .

It is a cyclic number.

It is not a de Polignac number, because 21634453 - 2¹ = 21634451 is a prime.

Together with 21634451, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21634451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10817226 + 10817227.

It is an arithmetic number, because the mean of its divisors is an integer number (10817227).

Almost surely, 2^21634453 is an apocalyptic number.

It is an amenable number.

21634453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21634453 is an equidigital number, since it uses as much as digits as its factorization.

21634453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 28.

The square root of 21634453 is about 4651.2850912409. The cubic root of 21634453 is about 278.6433223413.

The spelling of 21634453 in words is "twenty-one million, six hundred thirty-four thousand, four hundred fifty-three".