21854629 has 2 divisors, whose sum is σ = 21854630. Its totient is φ = 21854628.

The previous prime is 21854611. The next prime is 21854633. The reversal of 21854629 is 92645812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19342404 + 2512225 = 4398^2 + 1585^2 .

It is a cyclic number.

It is not a de Polignac number, because 21854629 - 2⁷ = 21854501 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21854689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927314 + 10927315.

It is an arithmetic number, because the mean of its divisors is an integer number (10927315).

Almost surely, 2^21854629 is an apocalyptic number.

It is an amenable number.

21854629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21854629 is an equidigital number, since it uses as much as digits as its factorization.

21854629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 37.

The square root of 21854629 is about 4674.8934747222. The cubic root of 21854629 is about 279.5853940343.

The spelling of 21854629 in words is "twenty-one million, eight hundred fifty-four thousand, six hundred twenty-nine".