1961098861 has 2 divisors, whose sum is σ = 1961098862. Its totient is φ = 1961098860.

The previous prime is 1961098847. The next prime is 1961098873. The reversal of 1961098861 is 1688901691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1131313225 + 829785636 = 33635^2 + 28806^2 .

It is an emirp because it is prime and its reverse (1688901691) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1988601961 and 1691068891.

It is a cyclic number.

It is not a de Polignac number, because 1961098861 - 2¹³ = 1961090669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1961098261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980549430 + 980549431.

It is an arithmetic number, because the mean of its divisors is an integer number (980549431).

Almost surely, 2^1961098861 is an apocalyptic number.

It is an amenable number.

1961098861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961098861 is an equidigital number, since it uses as much as digits as its factorization.

1961098861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 49.

The square root of 1961098861 is about 44284.2958733680. The cubic root of 1961098861 is about 1251.6987806163.

The spelling of 1961098861 in words is "one billion, nine hundred sixty-one million, ninety-eight thousand, eight hundred sixty-one".