21117459 has 16 divisors (see below), whose sum is σ = 31152384. Its totient is φ = 12616800.

The previous prime is 21117443. The next prime is 21117463. The reversal of 21117459 is 95471112.

It is not a de Polignac number, because 21117459 - 2⁴ = 21117443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21117409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2164 + ... + 6849.

It is an arithmetic number, because the mean of its divisors is an integer number (1947024).

Almost surely, 2^21117459 is an apocalyptic number.

21117459 is a deficient number, since it is larger than the sum of its proper divisors (10034925).

21117459 is a wasteful number, since it uses less digits than its factorization.

21117459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9098.

The product of its digits is 2520, while the sum is 30.

The square root of 21117459 is about 4595.3736518372. The cubic root of 21117459 is about 276.4058432852.

The spelling of 21117459 in words is "twenty-one million, one hundred seventeen thousand, four hundred fifty-nine".