21357443 has 2 divisors, whose sum is σ = 21357444. Its totient is φ = 21357442.

The previous prime is 21357431. The next prime is 21357451. The reversal of 21357443 is 34475312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21357443 - 2¹² = 21353347 is a prime.

It is a super-2 number, since 2×21357443² = 912280742996498, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21357403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678721 + 10678722.

It is an arithmetic number, because the mean of its divisors is an integer number (10678722).

Almost surely, 2^21357443 is an apocalyptic number.

21357443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357443 is an equidigital number, since it uses as much as digits as its factorization.

21357443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 29.

The square root of 21357443 is about 4621.4113645076. The cubic root of 21357443 is about 277.4489498387.

The spelling of 21357443 in words is "twenty-one million, three hundred fifty-seven thousand, four hundred forty-three".