21155154404536 has 16 divisors (see below), whose sum is σ = 39667412354400. Its totient is φ = 10577177776704.

The previous prime is 21155154404521. The next prime is 21155154404537. The reversal of 21155154404536 is 63540445155112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155154404537) 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 3 ways as a sum of consecutive naturals, for example, 49703040 + ... + 50126863.

It is an arithmetic number, because the mean of its divisors is an integer number (2479213272150).

Almost surely, 2^{21155154404536} is an apocalyptic number.

It is an amenable number.

21155154404536 is a deficient number, since it is larger than the sum of its proper divisors (18512257949864).

21155154404536 is a wasteful number, since it uses less digits than its factorization.

21155154404536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99856398 (or 99856394 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 46.

Adding to 21155154404536 its reverse (63540445155112), we get a palindrome (84695599559648).

The spelling of 21155154404536 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred fifty-four million, four hundred four thousand, five hundred thirty-six".