21535814 has 4 divisors (see below), whose sum is σ = 32303724. Its totient is φ = 10767906.

The previous prime is 21535781. The next prime is 21535837. The reversal of 21535814 is 41853512.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5383952 + ... + 5383955.

It is an arithmetic number, because the mean of its divisors is an integer number (8075931).

Almost surely, 2^21535814 is an apocalyptic number.

21535814 is a deficient number, since it is larger than the sum of its proper divisors (10767910).

21535814 is a wasteful number, since it uses less digits than its factorization.

21535814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10767909.

The product of its digits is 4800, while the sum is 29.

The square root of 21535814 is about 4640.6695637591. The cubic root of 21535814 is about 278.2191998213.

The spelling of 21535814 in words is "twenty-one million, five hundred thirty-five thousand, eight hundred fourteen".