21345130 has 16 divisors (see below), whose sum is σ = 38590344. Its totient is φ = 8500480.

The previous prime is 21345119. The next prime is 21345187. The reversal of 21345130 is 3154312.

It can be written as a sum of positive squares in 4 ways, for example, as 12327121 + 9018009 = 3511^2 + 3003^2 .

It is a super-2 number, since 2×21345130² = 911229149433800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21345098 and 21345107.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2251 + ... + 6910.

Almost surely, 2^21345130 is an apocalyptic number.

21345130 is a deficient number, since it is larger than the sum of its proper divisors (17245214).

21345130 is a wasteful number, since it uses less digits than its factorization.

21345130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9401.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21345130 is about 4620.0790036535. The cubic root of 21345130 is about 277.3956212693.

Adding to 21345130 its reverse (3154312), we get a palindrome (24499442).

The spelling of 21345130 in words is "twenty-one million, three hundred forty-five thousand, one hundred thirty".