21252451110 has 64 divisors (see below), whose sum is σ = 55757458944. Its totient is φ = 5141491200.

The previous prime is 21252451097. The next prime is 21252451123. The reversal of 21252451110 is 1115425212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21252451097) and next prime (21252451123).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 94590 + ... + 226830.

It is an arithmetic number, because the mean of its divisors is an integer number (871210296).

Almost surely, 2^21252451110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21252451110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27878729472).

21252451110 is an abundant number, since it is smaller than the sum of its proper divisors (34505007834).

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

21252451110 is a wasteful number, since it uses less digits than its factorization.

21252451110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132749.

The product of its (nonzero) digits is 800, while the sum is 24.

Adding to 21252451110 its reverse (1115425212), we get a palindrome (22367876322).

The spelling of 21252451110 in words is "twenty-one billion, two hundred fifty-two million, four hundred fifty-one thousand, one hundred ten".