21125459 has 8 divisors (see below), whose sum is σ = 21581952. Its totient is φ = 20672640.

The previous prime is 21125443. The next prime is 21125471. The reversal of 21125459 is 95452112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21125459 - 2⁴ = 21125443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12827 + ... + 14379.

It is an arithmetic number, because the mean of its divisors is an integer number (2697744).

Almost surely, 2^21125459 is an apocalyptic number.

21125459 is a deficient number, since it is larger than the sum of its proper divisors (456493).

21125459 is a wasteful number, since it uses less digits than its factorization.

21125459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1837.

The product of its digits is 3600, while the sum is 29.

The square root of 21125459 is about 4596.2440100586. The cubic root of 21125459 is about 276.4407428056.

The spelling of 21125459 in words is "twenty-one million, one hundred twenty-five thousand, four hundred fifty-nine".