21534689 has 8 divisors (see below), whose sum is σ = 23790720. Its totient is φ = 19328400.

The previous prime is 21534683. The next prime is 21534727. The reversal of 21534689 is 98643512.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21534689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21534683) 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, 11522 + ... + 13259.

It is an arithmetic number, because the mean of its divisors is an integer number (2973840).

Almost surely, 2^21534689 is an apocalyptic number.

It is an amenable number.

21534689 is a deficient number, since it is larger than the sum of its proper divisors (2256031).

21534689 is a wasteful number, since it uses less digits than its factorization.

21534689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24871.

The product of its digits is 51840, while the sum is 38.

The square root of 21534689 is about 4640.5483512189. The cubic root of 21534689 is about 278.2143551464.

The spelling of 21534689 in words is "twenty-one million, five hundred thirty-four thousand, six hundred eighty-nine".