4011955561 has 2 divisors, whose sum is σ = 4011955562. Its totient is φ = 4011955560.

The previous prime is 4011955531. The next prime is 4011955603. The reversal of 4011955561 is 1655591104.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3828515625 + 183439936 = 61875^2 + 13544^2 .

It is a cyclic number.

It is not a de Polignac number, because 4011955561 - 2¹⁵ = 4011922793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4011955561.

It is not a weakly prime, because it can be changed into another prime (4011955501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2005977780 + 2005977781.

It is an arithmetic number, because the mean of its divisors is an integer number (2005977781).

Almost surely, 2^4011955561 is an apocalyptic number.

It is an amenable number.

4011955561 is a deficient number, since it is larger than the sum of its proper divisors (1).

4011955561 is an equidigital number, since it uses as much as digits as its factorization.

4011955561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27000, while the sum is 37.

The square root of 4011955561 is about 63339.9996921377. Note that the first 3 decimals coincide. The cubic root of 4011955561 is about 1588.9810014227.

The spelling of 4011955561 in words is "four billion, eleven million, nine hundred fifty-five thousand, five hundred sixty-one".