1812945961 has 2 divisors, whose sum is σ = 1812945962. Its totient is φ = 1812945960.

The previous prime is 1812945929. The next prime is 1812945973. The reversal of 1812945961 is 1695492181.

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., 1643815936 + 169130025 = 40544^2 + 13005^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812945961 - 2⁵ = 1812945929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1812915961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 906472980 + 906472981.

It is an arithmetic number, because the mean of its divisors is an integer number (906472981).

Almost surely, 2^1812945961 is an apocalyptic number.

It is an amenable number.

1812945961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1812945961 is an equidigital number, since it uses as much as digits as its factorization.

1812945961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 46.

The square root of 1812945961 is about 42578.7031390107. The cubic root of 1812945961 is about 1219.3497298305.

The spelling of 1812945961 in words is "one billion, eight hundred twelve million, nine hundred forty-five thousand, nine hundred sixty-one".