21261232153446 has 16 divisors (see below), whose sum is σ = 42522515552064. Its totient is φ = 7087068843624.

The previous prime is 21261232153387. The next prime is 21261232153507. The reversal of 21261232153446 is 64435123216212.

It is a junction number, because it is equal to n+sod(n) for n = 21261232153398 and 21261232153407.

It is a congruent number.

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, 5193165 + ... + 8336151.

It is an arithmetic number, because the mean of its divisors is an integer number (2657657222004).

Almost surely, 2^{21261232153446} is an apocalyptic number.

21261232153446 is an abundant number, since it is smaller than the sum of its proper divisors (21261283398618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21261232153446 is a wasteful number, since it uses less digits than its factorization.

21261232153446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4270435.

The product of its digits is 414720, while the sum is 42.

Adding to 21261232153446 its reverse (64435123216212), we get a palindrome (85696355369658).

The spelling of 21261232153446 in words is "twenty-one trillion, two hundred sixty-one billion, two hundred thirty-two million, one hundred fifty-three thousand, four hundred forty-six".