1215631601 has 4 divisors (see below), whose sum is σ = 1226992752. Its totient is φ = 1204270452.

The previous prime is 1215631579. The next prime is 1215631619. The reversal of 1215631601 is 1061365121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215631601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215630601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5680415 + ... + 5680628.

It is an arithmetic number, because the mean of its divisors is an integer number (306748188).

Almost surely, 2^1215631601 is an apocalyptic number.

It is an amenable number.

1215631601 is a deficient number, since it is larger than the sum of its proper divisors (11361151).

1215631601 is a wasteful number, since it uses less digits than its factorization.

1215631601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11361150.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1215631601 is about 34865.9088652512. The cubic root of 1215631601 is about 1067.2528595119.

Adding to 1215631601 its reverse (1061365121), we get a palindrome (2276996722).

The spelling of 1215631601 in words is "one billion, two hundred fifteen million, six hundred thirty-one thousand, six hundred one".