21577222 has 4 divisors (see below), whose sum is σ = 32365836. Its totient is φ = 10788610.

The previous prime is 21577219. The next prime is 21577223. The reversal of 21577222 is 22277512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21577223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5394304 + ... + 5394307.

It is an arithmetic number, because the mean of its divisors is an integer number (8091459).

Almost surely, 2^21577222 is an apocalyptic number.

21577222 is a deficient number, since it is larger than the sum of its proper divisors (10788614).

21577222 is a wasteful number, since it uses less digits than its factorization.

21577222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10788613.

The product of its digits is 3920, while the sum is 28.

The square root of 21577222 is about 4645.1288464369. The cubic root of 21577222 is about 278.3974010387.

The spelling of 21577222 in words is "twenty-one million, five hundred seventy-seven thousand, two hundred twenty-two".