1961611811 has 2 divisors, whose sum is σ = 1961611812. Its totient is φ = 1961611810.

The previous prime is 1961611783. The next prime is 1961611819. The reversal of 1961611811 is 1181161691.

It is a strong prime.

It is an emirp because it is prime and its reverse (1181161691) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1181191961 and 1691911811.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1961611811 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961611819) 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, 980805905 + 980805906.

It is an arithmetic number, because the mean of its divisors is an integer number (980805906).

Almost surely, 2^1961611811 is an apocalyptic number.

1961611811 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961611811 is an equidigital number, since it uses as much as digits as its factorization.

1961611811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 35.

The square root of 1961611811 is about 44290.0870511676. The cubic root of 1961611811 is about 1251.8079036070.

The spelling of 1961611811 in words is "one billion, nine hundred sixty-one million, six hundred eleven thousand, eight hundred eleven".