1231515 has 12 divisors (see below), whose sum is σ = 2134704. Its totient is φ = 656784.

The previous prime is 1231513. The next prime is 1231547. The reversal of 1231515 is 5151321.

1231515 = T₁₈₆ + T₁₈₇ + ... + T₂₃₉.

It is not a de Polignac number, because 1231515 - 2¹ = 1231513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231511) 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, 13639 + ... + 13728.

It is an arithmetic number, because the mean of its divisors is an integer number (177892).

2^1231515 is an apocalyptic number.

1231515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1231515 is a deficient number, since it is larger than the sum of its proper divisors (903189).

1231515 is a wasteful number, since it uses less digits than its factorization.

1231515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27378 (or 27375 counting only the distinct ones).

The product of its digits is 150, while the sum is 18.

The square root of 1231515 is about 1109.7364552001. The cubic root of 1231515 is about 107.1880989889.

Adding to 1231515 its product of digits (150), we get a triangular number (1231665 = T₁₅₆₉).

Adding to 1231515 its reverse (5151321), we get a palindrome (6382836).

The spelling of 1231515 in words is "one million, two hundred thirty-one thousand, five hundred fifteen".