21541423 has 2 divisors, whose sum is σ = 21541424. Its totient is φ = 21541422.

The previous prime is 21541417. The next prime is 21541427. The reversal of 21541423 is 32414512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21541423 - 2⁵ = 21541391 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21541394 and 21541403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21541427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770711 + 10770712.

It is an arithmetic number, because the mean of its divisors is an integer number (10770712).

Almost surely, 2^21541423 is an apocalyptic number.

21541423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541423 is an equidigital number, since it uses as much as digits as its factorization.

21541423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 22.

The square root of 21541423 is about 4641.2738553117. The cubic root of 21541423 is about 278.2433517763.

Adding to 21541423 its reverse (32414512), we get a palindrome (53955935).

The spelling of 21541423 in words is "twenty-one million, five hundred forty-one thousand, four hundred twenty-three".