21842651 has 2 divisors, whose sum is σ = 21842652. Its totient is φ = 21842650.

The previous prime is 21842593. The next prime is 21842669. The reversal of 21842651 is 15624812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21842651 - 2¹⁴ = 21826267 is a prime.

It is not a weakly prime, because it can be changed into another prime (21842351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10921325 + 10921326.

It is an arithmetic number, because the mean of its divisors is an integer number (10921326).

Almost surely, 2^21842651 is an apocalyptic number.

21842651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21842651 is an equidigital number, since it uses as much as digits as its factorization.

21842651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3840, while the sum is 29.

The square root of 21842651 is about 4673.6122004291. The cubic root of 21842651 is about 279.5343066750.

The spelling of 21842651 in words is "twenty-one million, eight hundred forty-two thousand, six hundred fifty-one".