1215212666 has 16 divisors (see below), whose sum is σ = 1942833600. Its totient is φ = 568075200.

The previous prime is 1215212651. The next prime is 1215212693. The reversal of 1215212666 is 6662125121.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113216 + ... + 123483.

It is an arithmetic number, because the mean of its divisors is an integer number (121427100).

Almost surely, 2^1215212666 is an apocalyptic number.

1215212666 is a deficient number, since it is larger than the sum of its proper divisors (727620934).

1215212666 is a wasteful number, since it uses less digits than its factorization.

1215212666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236869.

The product of its digits is 8640, while the sum is 32.

The square root of 1215212666 is about 34859.9005448954. The cubic root of 1215212666 is about 1067.1302453505.

Adding to 1215212666 its reverse (6662125121), we get a palindrome (7877337787).

The spelling of 1215212666 in words is "one billion, two hundred fifteen million, two hundred twelve thousand, six hundred sixty-six".