21131024 has 20 divisors (see below), whose sum is σ = 42354060. Its totient is φ = 10200960.

The previous prime is 21131009. The next prime is 21131029. The reversal of 21131024 is 42013112.

It can be written as a sum of positive squares in 2 ways, for example, as 5607424 + 15523600 = 2368^2 + 3940^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22307 + ... + 23234.

It is an arithmetic number, because the mean of its divisors is an integer number (2117703).

Almost surely, 2^21131024 is an apocalyptic number.

It is an amenable number.

21131024 is an abundant number, since it is smaller than the sum of its proper divisors (21223036).

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

21131024 is a wasteful number, since it uses less digits than its factorization.

21131024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45578 (or 45572 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21131024 is about 4596.8493558088. The cubic root of 21131024 is about 276.4650145886.

Adding to 21131024 its reverse (42013112), we get a palindrome (63144136).

The spelling of 21131024 in words is "twenty-one million, one hundred thirty-one thousand, twenty-four".