21155422 has 4 divisors (see below), whose sum is σ = 31733136. Its totient is φ = 10577710.

The previous prime is 21155419. The next prime is 21155437. The reversal of 21155422 is 22455112.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21155393 and 21155402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288854 + ... + 5288857.

It is an arithmetic number, because the mean of its divisors is an integer number (7933284).

Almost surely, 2^21155422 is an apocalyptic number.

21155422 is a deficient number, since it is larger than the sum of its proper divisors (10577714).

21155422 is a wasteful number, since it uses less digits than its factorization.

21155422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10577713.

The product of its digits is 800, while the sum is 22.

The square root of 21155422 is about 4599.5023643868. The cubic root of 21155422 is about 276.5713763544.

The spelling of 21155422 in words is "twenty-one million, one hundred fifty-five thousand, four hundred twenty-two".