1868981 has 4 divisors (see below), whose sum is σ = 1919532. Its totient is φ = 1818432.

The previous prime is 1868947. The next prime is 1868983. The reversal of 1868981 is 1898681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1716100 + 152881 = 1310^2 + 391^2 .

It is a cyclic number.

It is not a de Polignac number, because 1868981 - 2⁶ = 1868917 is a prime.

It is a super-2 number, since 2×1868981² = 6986179956722, which contains 22 as substring.

1868981 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1868983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25220 + ... + 25293.

It is an arithmetic number, because the mean of its divisors is an integer number (479883).

2^1868981 is an apocalyptic number.

It is an amenable number.

1868981 is a deficient number, since it is larger than the sum of its proper divisors (50551).

1868981 is an equidigital number, since it uses as much as digits as its factorization.

1868981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50550.

The product of its digits is 27648, while the sum is 41.

The square root of 1868981 is about 1367.1067990468. The cubic root of 1868981 is about 123.1785144477.

The spelling of 1868981 in words is "one million, eight hundred sixty-eight thousand, nine hundred eighty-one".