1212151261 has 2 divisors, whose sum is σ = 1212151262. Its totient is φ = 1212151260.

The previous prime is 1212151247. The next prime is 1212151301. The reversal of 1212151261 is 1621512121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1142845636 + 69305625 = 33806^2 + 8325^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212151261 - 2¹⁵ = 1212118493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212151231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606075630 + 606075631.

It is an arithmetic number, because the mean of its divisors is an integer number (606075631).

Almost surely, 2^1212151261 is an apocalyptic number.

It is an amenable number.

1212151261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212151261 is an equidigital number, since it uses as much as digits as its factorization.

1212151261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 22.

The square root of 1212151261 is about 34815.9627326317. The cubic root of 1212151261 is about 1066.2333748731.

Adding to 1212151261 its reverse (1621512121), we get a palindrome (2833663382).

The spelling of 1212151261 in words is "one billion, two hundred twelve million, one hundred fifty-one thousand, two hundred sixty-one".