21045220402 has 8 divisors (see below), whose sum is σ = 31568582700. Its totient is φ = 10522359504.

The previous prime is 21045220379. The next prime is 21045220447. The reversal of 21045220402 is 20402254012.

It can be written as a sum of positive squares in 2 ways, for example, as 20315085961 + 730134441 = 142531^2 + 27021^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7924 + ... + 205312.

Almost surely, 2^21045220402 is an apocalyptic number.

21045220402 is a deficient number, since it is larger than the sum of its proper divisors (10523362298).

21045220402 is a wasteful number, since it uses less digits than its factorization.

21045220402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250700.

The product of its (nonzero) digits is 1280, while the sum is 22.

Adding to 21045220402 its reverse (20402254012), we get a palindrome (41447474414).

The spelling of 21045220402 in words is "twenty-one billion, forty-five million, two hundred twenty thousand, four hundred two".