1215738671 has 4 divisors (see below), whose sum is σ = 1389415632. Its totient is φ = 1042061712.

The previous prime is 1215738611. The next prime is 1215738673. The reversal of 1215738671 is 1768375121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215738671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215738673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86838470 + ... + 86838483.

It is an arithmetic number, because the mean of its divisors is an integer number (347353908).

Almost surely, 2^1215738671 is an apocalyptic number.

1215738671 is a deficient number, since it is larger than the sum of its proper divisors (173676961).

1215738671 is an equidigital number, since it uses as much as digits as its factorization.

1215738671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173676960.

The product of its digits is 70560, while the sum is 41.

The square root of 1215738671 is about 34867.4442854649. Note that the first 3 decimals coincide. The cubic root of 1215738671 is about 1067.2841923074.

The spelling of 1215738671 in words is "one billion, two hundred fifteen million, seven hundred thirty-eight thousand, six hundred seventy-one".