1231545 has 32 divisors (see below), whose sum is σ = 2320128. Its totient is φ = 546048.

The previous prime is 1231513. The next prime is 1231547. The reversal of 1231545 is 5451321.

It is not a de Polignac number, because 1231545 - 2⁵ = 1231513 is a prime.

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

It is an Ulam number.

1231545 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1231547) 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 31 ways as a sum of consecutive naturals, for example, 3727 + ... + 4043.

It is an arithmetic number, because the mean of its divisors is an integer number (72504).

2^1231545 is an apocalyptic number.

1231545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231545 is a deficient number, since it is larger than the sum of its proper divisors (1088583).

1231545 is a wasteful number, since it uses less digits than its factorization.

1231545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369.

The product of its digits is 600, while the sum is 21.

The square root of 1231545 is about 1109.7499718405. The cubic root of 1231545 is about 107.1889693577.

Adding to 1231545 its reverse (5451321), we get a palindrome (6682866).

The spelling of 1231545 in words is "one million, two hundred thirty-one thousand, five hundred forty-five".