21400330 has 16 divisors (see below), whose sum is σ = 44023680. Its totient is φ = 7337232.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400330 is 3300412.

It is a self number, because there is not a number n which added to its sum of digits gives 21400330.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152790 + ... + 152929.

It is an arithmetic number, because the mean of its divisors is an integer number (2751480).

Almost surely, 2^21400330 is an apocalyptic number.

21400330 is an abundant number, since it is smaller than the sum of its proper divisors (22623350).

21400330 is a wasteful number, since it uses less digits than its factorization.

21400330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305733.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 21400330 is about 4626.0490702110. The cubic root of 21400330 is about 277.6345369333.

Adding to 21400330 its reverse (3300412), we get a palindrome (24700742).

The spelling of 21400330 in words is "twenty-one million, four hundred thousand, three hundred thirty".