21163055540 has 48 divisors (see below), whose sum is σ = 51334565184. Its totient is φ = 7242969600.

The previous prime is 21163055539. The next prime is 21163055593. The reversal of 21163055540 is 4555036112.

It is a junction number, because it is equal to n+sod(n) for n = 21163055497 and 21163055506.

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 15 ways as a sum of consecutive naturals, for example, 2825546 + ... + 2833025.

It is an arithmetic number, because the mean of its divisors is an integer number (1069470108).

Almost surely, 2^21163055540 is an apocalyptic number.

21163055540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21163055540 is an abundant number, since it is smaller than the sum of its proper divisors (30171509644).

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

21163055540 is a wasteful number, since it uses less digits than its factorization.

21163055540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5658608 (or 5658606 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 32.

The spelling of 21163055540 in words is "twenty-one billion, one hundred sixty-three million, fifty-five thousand, five hundred forty".