21404030 has 32 divisors (see below), whose sum is σ = 41601600. Its totient is φ = 7904512.

The previous prime is 21404029. The next prime is 21404063. The reversal of 21404030 is 3040412.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21403996 and 21404014.

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, 5066 + ... + 8274.

It is an arithmetic number, because the mean of its divisors is an integer number (1300050).

Almost surely, 2^21404030 is an apocalyptic number.

21404030 is a deficient number, since it is larger than the sum of its proper divisors (20197570).

21404030 is a wasteful number, since it uses less digits than its factorization.

21404030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3268.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21404030 is about 4626.4489622171. The cubic root of 21404030 is about 277.6505365089.

Adding to 21404030 its reverse (3040412), we get a palindrome (24444442).

The spelling of 21404030 in words is "twenty-one million, four hundred four thousand, thirty".