1215639161 has 16 divisors (see below), whose sum is σ = 1358408448. Its totient is φ = 1078387200.

The previous prime is 1215639157. The next prime is 1215639199. The reversal of 1215639161 is 1619365121.

It is not a de Polignac number, because 1215639161 - 2² = 1215639157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215639121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179171 + ... + 185831.

It is an arithmetic number, because the mean of its divisors is an integer number (84900528).

Almost surely, 2^1215639161 is an apocalyptic number.

1215639161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1215639161 is a deficient number, since it is larger than the sum of its proper divisors (142769287).

1215639161 is a wasteful number, since it uses less digits than its factorization.

1215639161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7072.

The product of its digits is 9720, while the sum is 35.

The square root of 1215639161 is about 34866.0172804409. The cubic root of 1215639161 is about 1067.2550719187.

The spelling of 1215639161 in words is "one billion, two hundred fifteen million, six hundred thirty-nine thousand, one hundred sixty-one".