21193427 has 2 divisors, whose sum is σ = 21193428. Its totient is φ = 21193426.

The previous prime is 21193411. The next prime is 21193463. The reversal of 21193427 is 72439112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21193427 - 2⁴ = 21193411 is a prime.

It is a super-2 number, since 2×21193427² = 898322696008658, which contains 22 as substring.

It is equal to p_1341398 and since 21193427 and 1341398 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21193427.

It is not a weakly prime, because it can be changed into another prime (21193127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10596713 + 10596714.

It is an arithmetic number, because the mean of its divisors is an integer number (10596714).

Almost surely, 2^21193427 is an apocalyptic number.

21193427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21193427 is an equidigital number, since it uses as much as digits as its factorization.

21193427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 29.

The square root of 21193427 is about 4603.6319357655. The cubic root of 21193427 is about 276.7368943188.

The spelling of 21193427 in words is "twenty-one million, one hundred ninety-three thousand, four hundred twenty-seven".