21400422 has 32 divisors (see below), whose sum is σ = 45429120. Its totient is φ = 6701760.

The previous prime is 21400417. The next prime is 21400429. The reversal of 21400422 is 22400412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14218 + ... + 15650.

It is an arithmetic number, because the mean of its divisors is an integer number (1419660).

Almost surely, 2^21400422 is an apocalyptic number.

21400422 is an abundant number, since it is smaller than the sum of its proper divisors (24028698).

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

21400422 is a wasteful number, since it uses less digits than its factorization.

21400422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1588.

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 21400422 is about 4626.0590138908. The cubic root of 21400422 is about 277.6349347829.

Adding to 21400422 its reverse (22400412), we get a palindrome (43800834).

The spelling of 21400422 in words is "twenty-one million, four hundred thousand, four hundred twenty-two".