21511315110 has 128 divisors (see below), whose sum is σ = 55793857536. Its totient is φ = 5294615040.

The previous prime is 21511315103. The next prime is 21511315117. The reversal of 21511315110 is 1151311512.

It is an interprime number because it is at equal distance from previous prime (21511315103) and next prime (21511315117).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21511315117) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2225949 + ... + 2235591.

It is an arithmetic number, because the mean of its divisors is an integer number (435889512).

Almost surely, 2^21511315110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21511315110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27896928768).

21511315110 is an abundant number, since it is smaller than the sum of its proper divisors (34282542426).

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

21511315110 is a wasteful number, since it uses less digits than its factorization.

21511315110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9790.

The product of its (nonzero) digits is 150, while the sum is 21.

Adding to 21511315110 its reverse (1151311512), we get a palindrome (22662626622).

The spelling of 21511315110 in words is "twenty-one billion, five hundred eleven million, three hundred fifteen thousand, one hundred ten".