21540401044 has 24 divisors (see below), whose sum is σ = 37954859040. Its totient is φ = 10696310496.

The previous prime is 21540400969. The next prime is 21540401059. The reversal of 21540401044 is 44010404512.

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 7 ways as a sum of consecutive naturals, for example, 551779 + ... + 589525.

It is an arithmetic number, because the mean of its divisors is an integer number (1581452460).

Almost surely, 2^21540401044 is an apocalyptic number.

It is an amenable number.

21540401044 is a deficient number, since it is larger than the sum of its proper divisors (16414457996).

21540401044 is a wasteful number, since it uses less digits than its factorization.

21540401044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38727 (or 38725 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21540401044 its reverse (44010404512), we get a palindrome (65550805556).

The spelling of 21540401044 in words is "twenty-one billion, five hundred forty million, four hundred one thousand, forty-four".