21265043 has 2 divisors, whose sum is σ = 21265044. Its totient is φ = 21265042.

The previous prime is 21265001. The next prime is 21265051. The reversal of 21265043 is 34056212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21265043 - 2⁶ = 21264979 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21265093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632521 + 10632522.

It is an arithmetic number, because the mean of its divisors is an integer number (10632522).

Almost surely, 2^21265043 is an apocalyptic number.

21265043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265043 is an equidigital number, since it uses as much as digits as its factorization.

21265043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21265043 is about 4611.4035824248. The cubic root of 21265043 is about 277.0482566988.

The spelling of 21265043 in words is "twenty-one million, two hundred sixty-five thousand, forty-three".