21105160 has 64 divisors (see below), whose sum is σ = 51574320. Its totient is φ = 7741440.

The previous prime is 21105121. The next prime is 21105169. The reversal of 21105160 is 6150112.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7518564 + 13586596 = 2742^2 + 3686^2 .

It is not an unprimeable number, because it can be changed into a prime (21105169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27502 + ... + 28258.

Almost surely, 2^21105160 is an apocalyptic number.

21105160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21105160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25787160).

21105160 is an abundant number, since it is smaller than the sum of its proper divisors (30469160).

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

21105160 is a wasteful number, since it uses less digits than its factorization.

21105160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826 (or 822 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 21105160 is about 4594.0352632517. The cubic root of 21105160 is about 276.3521724396.

Adding to 21105160 its reverse (6150112), we get a palindrome (27255272).

The spelling of 21105160 in words is "twenty-one million, one hundred five thousand, one hundred sixty".