21300534 has 48 divisors (see below), whose sum is σ = 48522240. Its totient is φ = 6744240.

The previous prime is 21300527. The next prime is 21300551. The reversal of 21300534 is 43500312.

21300534 is a `hidden beast` number, since 2 + 130 + 0 + 534 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32599 + ... + 33245.

It is an arithmetic number, because the mean of its divisors is an integer number (1010880).

Almost surely, 2^21300534 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21300534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24261120).

21300534 is an abundant number, since it is smaller than the sum of its proper divisors (27221706).

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

21300534 is a wasteful number, since it uses less digits than its factorization.

21300534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745 (or 742 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21300534 is about 4615.2501557337. The cubic root of 21300534 is about 277.2023006624.

Adding to 21300534 its reverse (43500312), we get a palindrome (64800846).

The spelling of 21300534 in words is "twenty-one million, three hundred thousand, five hundred thirty-four".