21320104 has 32 divisors (see below), whose sum is σ = 44541000. Its totient is φ = 9499392.

The previous prime is 21320099. The next prime is 21320107. The reversal of 21320104 is 40102312.

It can be written as a sum of positive squares in 4 ways, for example, as 13468900 + 7851204 = 3670^2 + 2802^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (21320107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 519 + ... + 6550.

Almost surely, 2^21320104 is an apocalyptic number.

It is an amenable number.

21320104 is an abundant number, since it is smaller than the sum of its proper divisors (23220896).

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

21320104 is a wasteful number, since it uses less digits than its factorization.

21320104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7117 (or 7113 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21320104 is about 4617.3698140825. The cubic root of 21320104 is about 277.2871684643.

Adding to 21320104 its reverse (40102312), we get a palindrome (61422416).

The spelling of 21320104 in words is "twenty-one million, three hundred twenty thousand, one hundred four".