1215213101 has 2 divisors, whose sum is σ = 1215213102. Its totient is φ = 1215213100.

The previous prime is 1215213079. The next prime is 1215213137. The reversal of 1215213101 is 1013125121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1129632100 + 85581001 = 33610^2 + 9251^2 .

It is a cyclic number.

It is not a de Polignac number, because 1215213101 - 2¹⁰ = 1215212077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1215213101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1215213151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607606550 + 607606551.

It is an arithmetic number, because the mean of its divisors is an integer number (607606551).

Almost surely, 2^1215213101 is an apocalyptic number.

It is an amenable number.

1215213101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215213101 is an equidigital number, since it uses as much as digits as its factorization.

1215213101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 1215213101 is about 34859.9067841553. The cubic root of 1215213101 is about 1067.1303726812.

Adding to 1215213101 its reverse (1013125121), we get a palindrome (2228338222).

The spelling of 1215213101 in words is "one billion, two hundred fifteen million, two hundred thirteen thousand, one hundred one".