21242355351 has 8 divisors (see below), whose sum is σ = 32369303424. Its totient is φ = 12138488760.

The previous prime is 21242355347. The next prime is 21242355361. The reversal of 21242355351 is 15355324212.

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

It is not a de Polignac number, because 21242355351 - 2² = 21242355347 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242355311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 505770345 + ... + 505770386.

It is an arithmetic number, because the mean of its divisors is an integer number (4046162928).

Almost surely, 2^21242355351 is an apocalyptic number.

21242355351 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21242355351 is a deficient number, since it is larger than the sum of its proper divisors (11126948073).

21242355351 is a wasteful number, since it uses less digits than its factorization.

21242355351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1011540741.

The product of its digits is 36000, while the sum is 33.

Adding to 21242355351 its reverse (15355324212), we get a palindrome (36597679563).

The spelling of 21242355351 in words is "twenty-one billion, two hundred forty-two million, three hundred fifty-five thousand, three hundred fifty-one".