11661555151009 has 2 divisors, whose sum is σ = 11661555151010. Its totient is φ = 11661555151008.

The previous prime is 11661555150983. The next prime is 11661555151013. The reversal of 11661555151009 is 90015155516611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11297497380625 + 364057770384 = 3361175^2 + 603372^2 .

It is a cyclic number.

It is not a de Polignac number, because 11661555151009 - 2²⁵ = 11661521596577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11661555151009.

It is not a weakly prime, because it can be changed into another prime (11661555151049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5830777575504 + 5830777575505.

It is an arithmetic number, because the mean of its divisors is an integer number (5830777575505).

Almost surely, 2^{11661555151009} is an apocalyptic number.

It is an amenable number.

11661555151009 is a deficient number, since it is larger than the sum of its proper divisors (1).

11661555151009 is an equidigital number, since it uses as much as digits as its factorization.

11661555151009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 202500, while the sum is 46.

The spelling of 11661555151009 in words is "eleven trillion, six hundred sixty-one billion, five hundred fifty-five million, one hundred fifty-one thousand, nine".