21220035565642 has 8 divisors (see below), whose sum is σ = 31832254488132. Its totient is φ = 10609284069600.

The previous prime is 21220035565637. The next prime is 21220035565667. The reversal of 21220035565642 is 24656553002212.

It can be written as a sum of positive squares in 2 ways, for example, as 21202442461321 + 17593104321 = 4604611^2 + 132639^2 .

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

It is a super-2 number, since 2×21220035565642² (a number of 27 digits) contains 22 as substring.

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, 366820459 + ... + 366878302.

Almost surely, 2^{21220035565642} is an apocalyptic number.

21220035565642 is a deficient number, since it is larger than the sum of its proper divisors (10612218922490).

21220035565642 is a wasteful number, since it uses less digits than its factorization.

21220035565642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733713224.

The product of its (nonzero) digits is 864000, while the sum is 43.

Adding to 21220035565642 its reverse (24656553002212), we get a palindrome (45876588567854).

The spelling of 21220035565642 in words is "twenty-one trillion, two hundred twenty billion, thirty-five million, five hundred sixty-five thousand, six hundred forty-two".