21540233404 has 12 divisors (see below), whose sum is σ = 37709291200. Its totient is φ = 10766150208.

The previous prime is 21540233387. The next prime is 21540233467. The reversal of 21540233404 is 40433204512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979389 + ... + 1001140.

Almost surely, 2^21540233404 is an apocalyptic number.

It is an amenable number.

21540233404 is a deficient number, since it is larger than the sum of its proper divisors (16169057796).

21540233404 is a wasteful number, since it uses less digits than its factorization.

21540233404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1983252 (or 1983250 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 21540233404 its reverse (40433204512), we get a palindrome (61973437916).

The spelling of 21540233404 in words is "twenty-one billion, five hundred forty million, two hundred thirty-three thousand, four hundred four".