21430134 has 24 divisors (see below), whose sum is σ = 50653512. Its totient is φ = 6493920.

The previous prime is 21430121. The next prime is 21430139. The reversal of 21430134 is 43103412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53919 + ... + 54314.

It is an arithmetic number, because the mean of its divisors is an integer number (2110563).

Almost surely, 2^21430134 is an apocalyptic number.

21430134 is an abundant number, since it is smaller than the sum of its proper divisors (29223378).

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

21430134 is a wasteful number, since it uses less digits than its factorization.

21430134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108252 (or 108249 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21430134 is about 4629.2692727903. The cubic root of 21430134 is about 277.7633633172.

Adding to 21430134 its reverse (43103412), we get a palindrome (64533546).

The spelling of 21430134 in words is "twenty-one million, four hundred thirty thousand, one hundred thirty-four".