1851001961 has 2 divisors, whose sum is σ = 1851001962. Its totient is φ = 1851001960.

The previous prime is 1851001903. The next prime is 1851001963. The reversal of 1851001961 is 1691001581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1845217936 + 5784025 = 42956^2 + 2405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1851001961 is a prime.

It is a Sophie Germain prime.

Together with 1851001963, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1851001963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925500980 + 925500981.

It is an arithmetic number, because the mean of its divisors is an integer number (925500981).

Almost surely, 2^1851001961 is an apocalyptic number.

It is an amenable number.

1851001961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851001961 is an equidigital number, since it uses as much as digits as its factorization.

1851001961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 32.

The square root of 1851001961 is about 43023.2723185952. The cubic root of 1851001961 is about 1227.8226093202.

The spelling of 1851001961 in words is "one billion, eight hundred fifty-one million, one thousand, nine hundred sixty-one".