1861922549 has 2 divisors, whose sum is σ = 1861922550. Its totient is φ = 1861922548.

The previous prime is 1861922497. The next prime is 1861922567. The reversal of 1861922549 is 9452291681.

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., 1861922500 + 49 = 43150^2 + 7^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861922549 - 2²⁴ = 1845145333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861924549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930961274 + 930961275.

It is an arithmetic number, because the mean of its divisors is an integer number (930961275).

Almost surely, 2^1861922549 is an apocalyptic number.

It is an amenable number.

1861922549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861922549 is an equidigital number, since it uses as much as digits as its factorization.

1861922549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 47.

The square root of 1861922549 is about 43150.0005677868. Note that the first 3 decimals coincide. The cubic root of 1861922549 is about 1230.2325224142.

It can be divided in two parts, 18619225 and 49, that multiplied together give a square (912342025 = 30205²).

The spelling of 1861922549 in words is "one billion, eight hundred sixty-one million, nine hundred twenty-two thousand, five hundred forty-nine".