21220886 has 4 divisors (see below), whose sum is σ = 31831332. Its totient is φ = 10610442.

The previous prime is 21220877. The next prime is 21220907. The reversal of 21220886 is 68802212.

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, 5305220 + ... + 5305223.

It is an arithmetic number, because the mean of its divisors is an integer number (7957833).

Almost surely, 2^21220886 is an apocalyptic number.

21220886 is a deficient number, since it is larger than the sum of its proper divisors (10610446).

21220886 is a wasteful number, since it uses less digits than its factorization.

21220886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10610445.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 21220886 is about 4606.6132896088. The cubic root of 21220886 is about 276.8563596437.

The spelling of 21220886 in words is "twenty-one million, two hundred twenty thousand, eight hundred eighty-six".