21434130 has 24 divisors (see below), whose sum is σ = 55728972. Its totient is φ = 5715744.

The previous prime is 21434123. The next prime is 21434131. The reversal of 21434130 is 3143412.

It can be written as a sum of positive squares in 2 ways, for example, as 21372129 + 62001 = 4623^2 + 249^2 .

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 (21434131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118989 + ... + 119168.

Almost surely, 2^21434130 is an apocalyptic number.

21434130 is an abundant number, since it is smaller than the sum of its proper divisors (34294842).

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

21434130 is a wasteful number, since it uses less digits than its factorization.

21434130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238170 (or 238167 counting only the distinct ones).

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

The square root of 21434130 is about 4629.7008542669. The cubic root of 21434130 is about 277.7806267560.

Adding to 21434130 its reverse (3143412), we get a palindrome (24577542).

The spelling of 21434130 in words is "twenty-one million, four hundred thirty-four thousand, one hundred thirty".