21536434 has 16 divisors (see below), whose sum is σ = 33187968. Its totient is φ = 10476592.

The previous prime is 21536419. The next prime is 21536447. The reversal of 21536434 is 43463512.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17937 + ... + 19099.

It is an arithmetic number, because the mean of its divisors is an integer number (2074248).

Almost surely, 2^21536434 is an apocalyptic number.

21536434 is a deficient number, since it is larger than the sum of its proper divisors (11651534).

21536434 is a wasteful number, since it uses less digits than its factorization.

21536434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1409.

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

The square root of 21536434 is about 4640.7363639836. The cubic root of 21536434 is about 278.2218697033.

Adding to 21536434 its reverse (43463512), we get a palindrome (64999946).

The spelling of 21536434 in words is "twenty-one million, five hundred thirty-six thousand, four hundred thirty-four".