21448871 has 2 divisors, whose sum is σ = 21448872. Its totient is φ = 21448870.

The previous prime is 21448859. The next prime is 21448877. The reversal of 21448871 is 17884412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21448871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21448877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724435 + 10724436.

It is an arithmetic number, because the mean of its divisors is an integer number (10724436).

Almost surely, 2^21448871 is an apocalyptic number.

21448871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21448871 is an equidigital number, since it uses as much as digits as its factorization.

21448871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14336, while the sum is 35.

The square root of 21448871 is about 4631.2925841497. The cubic root of 21448871 is about 277.8442919770.

The spelling of 21448871 in words is "twenty-one million, four hundred forty-eight thousand, eight hundred seventy-one".