21533606 has 4 divisors (see below), whose sum is σ = 32300412. Its totient is φ = 10766802.

The previous prime is 21533597. The next prime is 21533647. The reversal of 21533606 is 60633512.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5383400 + ... + 5383403.

It is an arithmetic number, because the mean of its divisors is an integer number (8075103).

Almost surely, 2^21533606 is an apocalyptic number.

21533606 is a deficient number, since it is larger than the sum of its proper divisors (10766806).

21533606 is a wasteful number, since it uses less digits than its factorization.

21533606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10766805.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 21533606 is about 4640.4316609557. The cubic root of 21533606 is about 278.2096911800.

The spelling of 21533606 in words is "twenty-one million, five hundred thirty-three thousand, six hundred six".