13240731 has 12 divisors (see below), whose sum is σ = 20536872. Its totient is φ = 7566048.

The previous prime is 13240729. The next prime is 13240757. The reversal of 13240731 is 13704231.

It is not a de Polignac number, because 13240731 - 2¹ = 13240729 is a prime.

It is a super-2 number, since 2×13240731² = 350633914828722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 13240698 and 13240707.

It is not an unprimeable number, because it can be changed into a prime (13240771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44890 + ... + 45183.

It is an arithmetic number, because the mean of its divisors is an integer number (1711406).

Almost surely, 2^13240731 is an apocalyptic number.

13240731 is a deficient number, since it is larger than the sum of its proper divisors (7296141).

13240731 is an equidigital number, since it uses as much as digits as its factorization.

13240731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90090 (or 90083 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 13240731 is about 3638.7815268301. The cubic root of 13240731 is about 236.5759834638.

Adding to 13240731 its reverse (13704231), we get a palindrome (26944962).

The spelling of 13240731 in words is "thirteen million, two hundred forty thousand, seven hundred thirty-one".