1861421423 has 2 divisors, whose sum is σ = 1861421424. Its totient is φ = 1861421422.

The previous prime is 1861421411. The next prime is 1861421437. The reversal of 1861421423 is 3241241681.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1861421423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1861421423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861421483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930710711 + 930710712.

It is an arithmetic number, because the mean of its divisors is an integer number (930710712).

Almost surely, 2^1861421423 is an apocalyptic number.

1861421423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861421423 is an equidigital number, since it uses as much as digits as its factorization.

1861421423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 32.

The square root of 1861421423 is about 43144.1933868279. The cubic root of 1861421423 is about 1230.1221424522.

The spelling of 1861421423 in words is "one billion, eight hundred sixty-one million, four hundred twenty-one thousand, four hundred twenty-three".