21256153422133 has 16 divisors (see below), whose sum is σ = 25350449193216. Its totient is φ = 17426376760320.

The previous prime is 21256153422131. The next prime is 21256153422149. The reversal of 21256153422133 is 33122435165212.

It is a cyclic number.

It is not a de Polignac number, because 21256153422133 - 2¹ = 21256153422131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256153422131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1153516 + ... + 6621397.

It is an arithmetic number, because the mean of its divisors is an integer number (1584403074576).

Almost surely, 2^{21256153422133} is an apocalyptic number.

21256153422133 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21256153422133 is a deficient number, since it is larger than the sum of its proper divisors (4094295771083).

21256153422133 is a wasteful number, since it uses less digits than its factorization.

21256153422133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7791924.

The product of its digits is 259200, while the sum is 40.

Adding to 21256153422133 its reverse (33122435165212), we get a palindrome (54378588587345).

The spelling of 21256153422133 in words is "twenty-one trillion, two hundred fifty-six billion, one hundred fifty-three million, four hundred twenty-two thousand, one hundred thirty-three".