1231513 has 2 divisors, whose sum is σ = 1231514. Its totient is φ = 1231512.

The previous prime is 1231511. The next prime is 1231547. The reversal of 1231513 is 3151321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1194649 + 36864 = 1093^2 + 192^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231513 - 2¹ = 1231511 is a prime.

Together with 1231511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1231511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615756 + 615757.

It is an arithmetic number, because the mean of its divisors is an integer number (615757).

2^1231513 is an apocalyptic number.

It is an amenable number.

1231513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231513 is an equidigital number, since it uses as much as digits as its factorization.

1231513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90, while the sum is 16.

The square root of 1231513 is about 1109.7355540848. The cubic root of 1231513 is about 107.1880409638.

Adding to 1231513 its reverse (3151321), we get a palindrome (4382834).

The spelling of 1231513 in words is "one million, two hundred thirty-one thousand, five hundred thirteen".