21308130 has 32 divisors (see below), whose sum is σ = 56822400. Its totient is φ = 5682096.

The previous prime is 21308107. The next prime is 21308137. The reversal of 21308130 is 3180312.

It is a super-3 number, since 3×21308130³ (a number of 23 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21308137) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39190 + ... + 39729.

It is an arithmetic number, because the mean of its divisors is an integer number (1775700).

Almost surely, 2^21308130 is an apocalyptic number.

21308130 is an abundant number, since it is smaller than the sum of its proper divisors (35514270).

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

21308130 is a wasteful number, since it uses less digits than its factorization.

21308130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78935 (or 78929 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21308130 is about 4616.0730063551. The cubic root of 21308130 is about 277.2352478557.

Adding to 21308130 its reverse (3180312), we get a palindrome (24488442).

The spelling of 21308130 in words is "twenty-one million, three hundred eight thousand, one hundred thirty".