21694633 has 2 divisors, whose sum is σ = 21694634. Its totient is φ = 21694632.

The previous prime is 21694627. The next prime is 21694657. The reversal of 21694633 is 33649612.

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., 15896169 + 5798464 = 3987^2 + 2408^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21694633 is a prime.

It is not a weakly prime, because it can be changed into another prime (21694613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10847316 + 10847317.

It is an arithmetic number, because the mean of its divisors is an integer number (10847317).

Almost surely, 2^21694633 is an apocalyptic number.

It is an amenable number.

21694633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21694633 is an equidigital number, since it uses as much as digits as its factorization.

21694633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 34.

The square root of 21694633 is about 4657.7497785948. The cubic root of 21694633 is about 278.9014481298.

It can be divided in two parts, 216 and 94633, that added together give a palindrome (94849).

The spelling of 21694633 in words is "twenty-one million, six hundred ninety-four thousand, six hundred thirty-three".