21154422 has 16 divisors (see below), whose sum is σ = 42369840. Its totient is φ = 7041312.

The previous prime is 21154403. The next prime is 21154447. The reversal of 21154422 is 22445112.

It is a congruent number.

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, 2848 + ... + 7100.

It is an arithmetic number, because the mean of its divisors is an integer number (2648115).

Almost surely, 2^21154422 is an apocalyptic number.

21154422 is an abundant number, since it is smaller than the sum of its proper divisors (21215418).

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

21154422 is a wasteful number, since it uses less digits than its factorization.

21154422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5087.

The product of its digits is 640, while the sum is 21.

The square root of 21154422 is about 4599.3936556898. The cubic root of 21154422 is about 276.5670185160.

Adding to 21154422 its reverse (22445112), we get a palindrome (43599534).

The spelling of 21154422 in words is "twenty-one million, one hundred fifty-four thousand, four hundred twenty-two".