2661212009 has 2 divisors, whose sum is σ = 2661212010. Its totient is φ = 2661212008.

The previous prime is 2661212003. The next prime is 2661212017. The reversal of 2661212009 is 9002121662.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1753515625 + 907696384 = 41875^2 + 30128^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661212009 - 2⁸ = 2661211753 is a prime.

It is not a weakly prime, because it can be changed into another prime (2661212003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330606004 + 1330606005.

It is an arithmetic number, because the mean of its divisors is an integer number (1330606005).

Almost surely, 2^2661212009 is an apocalyptic number.

It is an amenable number.

2661212009 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661212009 is an equidigital number, since it uses as much as digits as its factorization.

2661212009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 2661212009 is about 51586.9364180506. The cubic root of 2661212009 is about 1385.7763911893.

The spelling of 2661212009 in words is "two billion, six hundred sixty-one million, two hundred twelve thousand, nine".