21220354 has 4 divisors (see below), whose sum is σ = 31830534. Its totient is φ = 10610176.

The previous prime is 21220349. The next prime is 21220357. The reversal of 21220354 is 45302212.

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

It can be written as a sum of positive squares in only one way, i.e., 20912329 + 308025 = 4573^2 + 555^2 .

It is not an unprimeable number, because it can be changed into a prime (21220357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305087 + ... + 5305090.

Almost surely, 2^21220354 is an apocalyptic number.

21220354 is a deficient number, since it is larger than the sum of its proper divisors (10610180).

21220354 is a wasteful number, since it uses less digits than its factorization.

21220354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10610179.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21220354 is about 4606.5555461755. Note that the first 4 decimals coincide. The cubic root of 21220354 is about 276.8540460612.

Adding to 21220354 its reverse (45302212), we get a palindrome (66522566).

The spelling of 21220354 in words is "twenty-one million, two hundred twenty thousand, three hundred fifty-four".