12640831 has 4 divisors (see below), whose sum is σ = 14446672. Its totient is φ = 10834992.

The previous prime is 12640829. The next prime is 12640841. The reversal of 12640831 is 13804621.

12640831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13804621 = 19 ⋅726559.

It is not a de Polignac number, because 12640831 - 2¹ = 12640829 is a prime.

It is a super-2 number, since 2×12640831² = 319581216741122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12640796 and 12640805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640841) 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, 902910 + ... + 902923.

It is an arithmetic number, because the mean of its divisors is an integer number (3611668).

Almost surely, 2^12640831 is an apocalyptic number.

12640831 is a deficient number, since it is larger than the sum of its proper divisors (1805841).

12640831 is an equidigital number, since it uses as much as digits as its factorization.

12640831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805840.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 12640831 is about 3555.3946335112. The cubic root of 12640831 is about 232.9477616256.

The spelling of 12640831 in words is "twelve million, six hundred forty thousand, eight hundred thirty-one".