21534006 has 32 divisors (see below), whose sum is σ = 47265120. Its totient is φ = 6499584.

The previous prime is 21533999. The next prime is 21534031. The reversal of 21534006 is 60043512.

It is a happy number.

It is a plaindrome in base 11.

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 in 15 ways as a sum of consecutive naturals, for example, 1530 + ... + 6738.

It is an arithmetic number, because the mean of its divisors is an integer number (1477035).

Almost surely, 2^21534006 is an apocalyptic number.

21534006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21534006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23632560).

21534006 is an abundant number, since it is smaller than the sum of its proper divisors (25731114).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21534006 is a wasteful number, since it uses less digits than its factorization.

21534006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5280.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21534006 is about 4640.4747601943. The cubic root of 21534006 is about 278.2114138082.

Adding to 21534006 its reverse (60043512), we get a palindrome (81577518).

The spelling of 21534006 in words is "twenty-one million, five hundred thirty-four thousand, six".