21423030 has 32 divisors (see below), whose sum is σ = 52614144. Its totient is φ = 5579616.

The previous prime is 21423019. The next prime is 21423053. The reversal of 21423030 is 3032412.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7014 + ... + 9593.

It is an arithmetic number, because the mean of its divisors is an integer number (1644192).

Almost surely, 2^21423030 is an apocalyptic number.

21423030 is an abundant number, since it is smaller than the sum of its proper divisors (31191114).

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

21423030 is a wasteful number, since it uses less digits than its factorization.

21423030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16660.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21423030 is about 4628.5019174675. The cubic root of 21423030 is about 277.7326674598.

Adding to 21423030 its reverse (3032412), we get a palindrome (24455442).

The spelling of 21423030 in words is "twenty-one million, four hundred twenty-three thousand, thirty".