1885981 has 2 divisors, whose sum is σ = 1885982. Its totient is φ = 1885980.

The previous prime is 1885979. The next prime is 1885991. The reversal of 1885981 is 1895881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1229881 + 656100 = 1109^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 1885981 - 2¹ = 1885979 is a prime.

It is a super-2 number, since 2×1885981² = 7113848664722, which contains 22 as substring.

Together with 1885979, it forms a pair of twin primes.

1885981 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1885991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 942990 + 942991.

It is an arithmetic number, because the mean of its divisors is an integer number (942991).

2^1885981 is an apocalyptic number.

It is an amenable number.

1885981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1885981 is an equidigital number, since it uses as much as digits as its factorization.

1885981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 40.

The square root of 1885981 is about 1373.3102344336. The cubic root of 1885981 is about 123.5508595234.

The spelling of 1885981 in words is "one million, eight hundred eighty-five thousand, nine hundred eighty-one".