21155100424 has 64 divisors (see below), whose sum is σ = 42669244800. Its totient is φ = 9797428224.

The previous prime is 21155100401. The next prime is 21155100457. The reversal of 21155100424 is 42400155112.

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 15 ways as a sum of consecutive naturals, for example, 3032989 + ... + 3039955.

It is an arithmetic number, because the mean of its divisors is an integer number (666706950).

Almost surely, 2^21155100424 is an apocalyptic number.

It is an amenable number.

21155100424 is an abundant number, since it is smaller than the sum of its proper divisors (21514144376).

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

21155100424 is a wasteful number, since it uses less digits than its factorization.

21155100424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7342 (or 7338 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21155100424 its reverse (42400155112), we get a palindrome (63555255536).

The spelling of 21155100424 in words is "twenty-one billion, one hundred fifty-five million, one hundred thousand, four hundred twenty-four".