21436534 has 8 divisors (see below), whose sum is σ = 36748368. Its totient is φ = 9187080.

The previous prime is 21436517. The next prime is 21436549. The reversal of 21436534 is 43563412.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 765577 + ... + 765604.

It is an arithmetic number, because the mean of its divisors is an integer number (4593546).

Almost surely, 2^21436534 is an apocalyptic number.

21436534 is a deficient number, since it is larger than the sum of its proper divisors (15311834).

21436534 is a wasteful number, since it uses less digits than its factorization.

21436534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1531190.

The product of its digits is 8640, while the sum is 28.

The square root of 21436534 is about 4629.9604749933. The cubic root of 21436534 is about 277.7910114347.

Adding to 21436534 its reverse (43563412), we get a palindrome (64999946).

The spelling of 21436534 in words is "twenty-one million, four hundred thirty-six thousand, five hundred thirty-four".