1861995151 has 2 divisors, whose sum is σ = 1861995152. Its totient is φ = 1861995150.

The previous prime is 1861995143. The next prime is 1861995167. The reversal of 1861995151 is 1515991681.

It is a weak prime.

It is an emirp because it is prime and its reverse (1515991681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861995151 - 2³ = 1861995143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861995131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930997575 + 930997576.

It is an arithmetic number, because the mean of its divisors is an integer number (930997576).

Almost surely, 2^1861995151 is an apocalyptic number.

1861995151 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861995151 is an equidigital number, since it uses as much as digits as its factorization.

1861995151 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 46.

The square root of 1861995151 is about 43150.8418341983. The cubic root of 1861995151 is about 1230.2485123705.

The spelling of 1861995151 in words is "one billion, eight hundred sixty-one million, nine hundred ninety-five thousand, one hundred fifty-one".