21481927 has 2 divisors, whose sum is σ = 21481928. Its totient is φ = 21481926.

The previous prime is 21481921. The next prime is 21481939. The reversal of 21481927 is 72918412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21481927 - 2³ = 21481919 is a prime.

It is a super-2 number, since 2×21481927² = 922946375266658, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21481892 and 21481901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21481921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10740963 + 10740964.

It is an arithmetic number, because the mean of its divisors is an integer number (10740964).

Almost surely, 2^21481927 is an apocalyptic number.

21481927 is a deficient number, since it is larger than the sum of its proper divisors (1).

21481927 is an equidigital number, since it uses as much as digits as its factorization.

21481927 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 34.

The square root of 21481927 is about 4634.8599763100. The cubic root of 21481927 is about 277.9869522714.

The spelling of 21481927 in words is "twenty-one million, four hundred eighty-one thousand, nine hundred twenty-seven".