21261421131633 has 24 divisors (see below), whose sum is σ = 31467065849856. Its totient is φ = 13825455883200.

The previous prime is 21261421131631. The next prime is 21261421131673. The reversal of 21261421131633 is 33613112416212.

21261421131633 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 1 + 4 + 2 + 1 + 13 + 1 + 633 = 666.

It is not a de Polignac number, because 21261421131633 - 2¹ = 21261421131631 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21261421131631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4837473 + ... + 8119358.

It is an arithmetic number, because the mean of its divisors is an integer number (1311127743744).

Almost surely, 2^{21261421131633} is an apocalyptic number.

It is an amenable number.

21261421131633 is a deficient number, since it is larger than the sum of its proper divisors (10205644718223).

21261421131633 is a wasteful number, since it uses less digits than its factorization.

21261421131633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12961325 (or 12961322 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

Adding to 21261421131633 its reverse (33613112416212), we get a palindrome (54874533547845).

The spelling of 21261421131633 in words is "twenty-one trillion, two hundred sixty-one billion, four hundred twenty-one million, one hundred thirty-one thousand, six hundred thirty-three".