1213529861 has 2 divisors, whose sum is σ = 1213529862. Its totient is φ = 1213529860.

The previous prime is 1213529783. The next prime is 1213529899. The reversal of 1213529861 is 1689253121.

It is a happy number.

It is an a-pointer prime, because the next prime (1213529899) can be obtained adding 1213529861 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1183772836 + 29757025 = 34406^2 + 5455^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213529861 - 2²² = 1209335557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213529761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606764930 + 606764931.

It is an arithmetic number, because the mean of its divisors is an integer number (606764931).

Almost surely, 2^1213529861 is an apocalyptic number.

It is an amenable number.

1213529861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213529861 is an equidigital number, since it uses as much as digits as its factorization.

1213529861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 1213529861 is about 34835.7554963288. The cubic root of 1213529861 is about 1066.6374367750.

The spelling of 1213529861 in words is "one billion, two hundred thirteen million, five hundred twenty-nine thousand, eight hundred sixty-one".