1231655 has 8 divisors (see below), whose sum is σ = 1484592. Its totient is φ = 980928.

The previous prime is 1231631. The next prime is 1231663. The reversal of 1231655 is 5561321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1231655 - 2¹⁰ = 1230631 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231655.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1172 + ... + 1958.

It is an arithmetic number, because the mean of its divisors is an integer number (185574).

2^1231655 is an apocalyptic number.

1231655 is a deficient number, since it is larger than the sum of its proper divisors (252937).

1231655 is an equidigital number, since it uses as much as digits as its factorization.

1231655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105.

The product of its digits is 900, while the sum is 23.

The square root of 1231655 is about 1109.7995314470. The cubic root of 1231655 is about 107.1921605892.

Adding to 1231655 its reverse (5561321), we get a palindrome (6792976).

The spelling of 1231655 in words is "one million, two hundred thirty-one thousand, six hundred fifty-five".