21121504110 has 384 divisors, whose sum is σ = 67749986304. Its totient is φ = 4634340480.

The previous prime is 21121504073. The next prime is 21121504111. The reversal of 21121504110 is 1140512112.

It is a super-2 number, since 2×21121504110² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121504111) by changing a digit.

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 191 ways as a sum of consecutive naturals, for example, 49005595 + ... + 49006025.

It is an arithmetic number, because the mean of its divisors is an integer number (176432256).

Almost surely, 2^21121504110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121504110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33874993152).

21121504110 is an abundant number, since it is smaller than the sum of its proper divisors (46628482194).

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

21121504110 is a wasteful number, since it uses less digits than its factorization.

21121504110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The spelling of 21121504110 in words is "twenty-one billion, one hundred twenty-one million, five hundred four thousand, one hundred ten".