21013306 has 8 divisors (see below), whose sum is σ = 32890464. Its totient is φ = 10049820.

The previous prime is 21013303. The next prime is 21013357. The reversal of 21013306 is 60331012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21013306.

It is not an unprimeable number, because it can be changed into a prime (21013301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 228360 + ... + 228451.

It is an arithmetic number, because the mean of its divisors is an integer number (4111308).

Almost surely, 2^21013306 is an apocalyptic number.

21013306 is a deficient number, since it is larger than the sum of its proper divisors (11877158).

21013306 is a wasteful number, since it uses less digits than its factorization.

21013306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456836.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 21013306 is about 4584.0272686798. The cubic root of 21013306 is about 275.9506755657.

Adding to 21013306 its reverse (60331012), we get a palindrome (81344318).

The spelling of 21013306 in words is "twenty-one million, thirteen thousand, three hundred six".