1215661137 has 8 divisors (see below), whose sum is σ = 1629937440. Its totient is φ = 805912800.

The previous prime is 1215661099. The next prime is 1215661163. The reversal of 1215661137 is 7311665121.

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

It is not a de Polignac number, because 1215661137 - 2¹² = 1215657041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1215661098 and 1215661107.

It is not an unprimeable number, because it can be changed into a prime (1215668137) 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, 1131364 + ... + 1132437.

It is an arithmetic number, because the mean of its divisors is an integer number (203742180).

Almost surely, 2^1215661137 is an apocalyptic number.

It is an amenable number.

1215661137 is a deficient number, since it is larger than the sum of its proper divisors (414276303).

1215661137 is a wasteful number, since it uses less digits than its factorization.

1215661137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2263983.

The product of its digits is 7560, while the sum is 33.

The square root of 1215661137 is about 34866.3324282896. The cubic root of 1215661137 is about 1067.2615030640.

The spelling of 1215661137 in words is "one billion, two hundred fifteen million, six hundred sixty-one thousand, one hundred thirty-seven".