21220402 has 16 divisors (see below), whose sum is σ = 37632960. Its totient is φ = 8780688.

The previous prime is 21220393. The next prime is 21220417. The reversal of 21220402 is 20402212.

It is a super-2 number, since 2×21220402² = 900610922083208, which contains 22 as substring.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 25728 + ... + 26539.

It is an arithmetic number, because the mean of its divisors is an integer number (2352060).

Almost surely, 2^21220402 is an apocalyptic number.

21220402 is a deficient number, since it is larger than the sum of its proper divisors (16412558).

21220402 is a wasteful number, since it uses less digits than its factorization.

21220402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52305.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21220402 is about 4606.5607561390. The cubic root of 21220402 is about 276.8542548071.

Adding to 21220402 its reverse (20402212), we get a palindrome (41622614).

The spelling of 21220402 in words is "twenty-one million, two hundred twenty thousand, four hundred two".