21259063 has 4 divisors (see below), whose sum is σ = 24296080. Its totient is φ = 18222048.

The previous prime is 21259037. The next prime is 21259093. The reversal of 21259063 is 36095212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21259063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21259013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1518498 + ... + 1518511.

It is an arithmetic number, because the mean of its divisors is an integer number (6074020).

Almost surely, 2^21259063 is an apocalyptic number.

21259063 is a deficient number, since it is larger than the sum of its proper divisors (3037017).

21259063 is an equidigital number, since it uses as much as digits as its factorization.

21259063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3037016.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21259063 is about 4610.7551442253. The cubic root of 21259063 is about 277.0222844353.

The spelling of 21259063 in words is "twenty-one million, two hundred fifty-nine thousand, sixty-three".