1215231631 has 8 divisors (see below), whose sum is σ = 1267038720. Its totient is φ = 1164084768.

The previous prime is 1215231629. The next prime is 1215231637. The reversal of 1215231631 is 1361325121.

It is a happy number.

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 1215231631 - 2¹ = 1215231629 is a prime.

It is a super-2 number, since 2×1215231631² = 2953575833965840322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1215231596 and 1215231605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215231637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161296 + ... + 168661.

It is an arithmetic number, because the mean of its divisors is an integer number (158379840).

Almost surely, 2^1215231631 is an apocalyptic number.

1215231631 is a deficient number, since it is larger than the sum of its proper divisors (51807089).

1215231631 is a wasteful number, since it uses less digits than its factorization.

1215231631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330113.

The product of its digits is 1080, while the sum is 25.

The square root of 1215231631 is about 34860.1725612482. The cubic root of 1215231631 is about 1067.1357966476.

Adding to 1215231631 its reverse (1361325121), we get a palindrome (2576556752).

The spelling of 1215231631 in words is "one billion, two hundred fifteen million, two hundred thirty-one thousand, six hundred thirty-one".