21770222 has 4 divisors (see below), whose sum is σ = 32655336. Its totient is φ = 10885110.

The previous prime is 21770179. The next prime is 21770237. The reversal of 21770222 is 22207712.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5442554 + ... + 5442557.

It is an arithmetic number, because the mean of its divisors is an integer number (8163834).

Almost surely, 2^21770222 is an apocalyptic number.

21770222 is a deficient number, since it is larger than the sum of its proper divisors (10885114).

21770222 is a wasteful number, since it uses less digits than its factorization.

21770222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10885113.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 21770222 is about 4665.8570488175. The cubic root of 21770222 is about 279.2249911949.

Adding to 21770222 its reverse (22207712), we get a palindrome (43977934).

The spelling of 21770222 in words is "twenty-one million, seven hundred seventy thousand, two hundred twenty-two".