21220343402 has 16 divisors (see below), whose sum is σ = 32418309024. Its totient is φ = 10414950000.

The previous prime is 21220343377. The next prime is 21220343429. The reversal of 21220343402 is 20434302212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117224 + ... + 237027.

It is an arithmetic number, because the mean of its divisors is an integer number (2026144314).

Almost surely, 2^21220343402 is an apocalyptic number.

21220343402 is a deficient number, since it is larger than the sum of its proper divisors (11197965622).

21220343402 is a wasteful number, since it uses less digits than its factorization.

21220343402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354805.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21220343402 its reverse (20434302212), we get a palindrome (41654645614).

The spelling of 21220343402 in words is "twenty-one billion, two hundred twenty million, three hundred forty-three thousand, four hundred two".