21145759 has 8 divisors (see below), whose sum is σ = 21792240. Its totient is φ = 20503296.

The previous prime is 21145757. The next prime is 21145769. The reversal of 21145759 is 95754112.

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 21145759 - 2¹ = 21145757 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 (21145753) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12252 + ... + 13870.

It is an arithmetic number, because the mean of its divisors is an integer number (2724030).

Almost surely, 2^21145759 is an apocalyptic number.

21145759 is a deficient number, since it is larger than the sum of its proper divisors (646481).

21145759 is a wasteful number, since it uses less digits than its factorization.

21145759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2009.

The product of its digits is 12600, while the sum is 34.

The square root of 21145759 is about 4598.4518046838. The cubic root of 21145759 is about 276.5292608121.

It can be divided in two parts, 21145 and 759, that added together give a square (21904 = 148²).

The spelling of 21145759 in words is "twenty-one million, one hundred forty-five thousand, seven hundred fifty-nine".