21115146 has 32 divisors (see below), whose sum is σ = 45779328. Its totient is φ = 6454080.

The previous prime is 21115141. The next prime is 21115189. The reversal of 21115146 is 64151112.

It is not an unprimeable number, because it can be changed into a prime (21115141) 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, 12216 + ... + 13836.

It is an arithmetic number, because the mean of its divisors is an integer number (1430604).

Almost surely, 2^21115146 is an apocalyptic number.

21115146 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21115146, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22889664).

21115146 is an abundant number, since it is smaller than the sum of its proper divisors (24664182).

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

21115146 is a wasteful number, since it uses less digits than its factorization.

21115146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806.

The product of its digits is 240, while the sum is 21.

The square root of 21115146 is about 4595.1219787945. The cubic root of 21115146 is about 276.3957513189.

Adding to 21115146 its reverse (64151112), we get a palindrome (85266258).

The spelling of 21115146 in words is "twenty-one million, one hundred fifteen thousand, one hundred forty-six".