21040331 has 12 divisors (see below), whose sum is σ = 23778288. Its totient is φ = 18573984.

The previous prime is 21040297. The next prime is 21040387. The reversal of 21040331 is 13304012.

It is not a de Polignac number, because 21040331 - 2⁶ = 21040267 is a prime.

It is a super-2 number, since 2×21040331² = 885391057179122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21040231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1181 + ... + 6593.

It is an arithmetic number, because the mean of its divisors is an integer number (1981524).

Almost surely, 2^21040331 is an apocalyptic number.

21040331 is a deficient number, since it is larger than the sum of its proper divisors (2737957).

21040331 is a wasteful number, since it uses less digits than its factorization.

21040331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5462 (or 5449 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21040331 is about 4586.9740570446. The cubic root of 21040331 is about 276.0689240104.

Adding to 21040331 its reverse (13304012), we get a palindrome (34344343).

The spelling of 21040331 in words is "twenty-one million, forty thousand, three hundred thirty-one".