1863803981 has 8 divisors (see below), whose sum is σ = 2008813464. Its totient is φ = 1719028800.

The previous prime is 1863803869. The next prime is 1863803983. The reversal of 1863803981 is 1893083681.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 586756 + 1863217225 = 766^2 + 43165^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1863803981 - 2¹⁸ = 1863541837 is a prime.

It is a super-2 number, since 2×1863803981² = 6947530559182896722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1863803983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41870 + ... + 74031.

It is an arithmetic number, because the mean of its divisors is an integer number (251101683).

Almost surely, 2^1863803981 is an apocalyptic number.

It is an amenable number.

1863803981 is a deficient number, since it is larger than the sum of its proper divisors (145009483).

1863803981 is a wasteful number, since it uses less digits than its factorization.

1863803981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117151.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 1863803981 is about 43171.7961289544. The cubic root of 1863803981 is about 1230.6467572699.

The spelling of 1863803981 in words is "one billion, eight hundred sixty-three million, eight hundred three thousand, nine hundred eighty-one".