21355444115 has 8 divisors (see below), whose sum is σ = 27133976160. Its totient is φ = 16079393152.

The previous prime is 21355444069. The next prime is 21355444129. The reversal of 21355444115 is 51144455312.

It is a happy number.

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

It is not a de Polignac number, because 21355444115 - 2¹² = 21355440019 is a prime.

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, 125620175 + ... + 125620344.

It is an arithmetic number, because the mean of its divisors is an integer number (3391747020).

Almost surely, 2^21355444115 is an apocalyptic number.

21355444115 is a deficient number, since it is larger than the sum of its proper divisors (5778532045).

21355444115 is a wasteful number, since it uses less digits than its factorization.

21355444115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251240541.

The product of its digits is 48000, while the sum is 35.

Adding to 21355444115 its reverse (51144455312), we get a palindrome (72499899427).

The spelling of 21355444115 in words is "twenty-one billion, three hundred fifty-five million, four hundred forty-four thousand, one hundred fifteen".