21100423351 has 4 divisors (see below), whose sum is σ = 24114769552. Its totient is φ = 18086077152.

The previous prime is 21100423349. The next prime is 21100423363. The reversal of 21100423351 is 15332400112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21100423351 - 2¹ = 21100423349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100423391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1507173090 + ... + 1507173103.

It is an arithmetic number, because the mean of its divisors is an integer number (6028692388).

Almost surely, 2^21100423351 is an apocalyptic number.

21100423351 is a deficient number, since it is larger than the sum of its proper divisors (3014346201).

21100423351 is an equidigital number, since it uses as much as digits as its factorization.

21100423351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3014346200.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21100423351 its reverse (15332400112), we get a palindrome (36432823463).

The spelling of 21100423351 in words is "twenty-one billion, one hundred million, four hundred twenty-three thousand, three hundred fifty-one".