1231235655 has 64 divisors (see below), whose sum is σ = 2224115712. Its totient is φ = 577082880.

The previous prime is 1231235623. The next prime is 1231235669. The reversal of 1231235655 is 5565321321.

It is a happy number.

It is not a de Polignac number, because 1231235655 - 2⁵ = 1231235623 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1214929 + ... + 1215941.

It is an arithmetic number, because the mean of its divisors is an integer number (34751808).

Almost surely, 2^1231235655 is an apocalyptic number.

1231235655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1231235655 is a deficient number, since it is larger than the sum of its proper divisors (992880057).

1231235655 is a wasteful number, since it uses less digits than its factorization.

1231235655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328.

The product of its digits is 27000, while the sum is 33.

The square root of 1231235655 is about 35088.9677106637. The cubic root of 1231235655 is about 1071.7999387070.

Adding to 1231235655 its reverse (5565321321), we get a palindrome (6796556976).

It can be divided in two parts, 123123 and 5655, that added together give a triangular number (128778 = T₅₀₇).

The spelling of 1231235655 in words is "one billion, two hundred thirty-one million, two hundred thirty-five thousand, six hundred fifty-five".