21494633 has 2 divisors, whose sum is σ = 21494634. Its totient is φ = 21494632.

The previous prime is 21494621. The next prime is 21494639. The reversal of 21494633 is 33649412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21049744 + 444889 = 4588^2 + 667^2 .

It is a cyclic number.

It is not a de Polignac number, because 21494633 - 2⁴ = 21494617 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21494633.

It is not a weakly prime, because it can be changed into another prime (21494639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10747316 + 10747317.

It is an arithmetic number, because the mean of its divisors is an integer number (10747317).

Almost surely, 2^21494633 is an apocalyptic number.

It is an amenable number.

21494633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21494633 is an equidigital number, since it uses as much as digits as its factorization.

21494633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 32.

The square root of 21494633 is about 4636.2304731322. The cubic root of 21494633 is about 278.0417488152.

The spelling of 21494633 in words is "twenty-one million, four hundred ninety-four thousand, six hundred thirty-three".