383653981 has 4 divisors (see below), whose sum is σ = 383712700. Its totient is φ = 383595264.

The previous prime is 383653951. The next prime is 383654003. The reversal of 383653981 is 189356383.

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 124121881 + 259532100 = 11141^2 + 16110^2 .

It is a cyclic number.

It is not a de Polignac number, because 383653981 - 2¹⁹ = 383129693 is a prime.

It is a super-2 number, since 2×383653981² = 294380754274296722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (383653901) 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, 18126 + ... + 33103.

It is an arithmetic number, because the mean of its divisors is an integer number (95928175).

Almost surely, 2^383653981 is an apocalyptic number.

It is an amenable number.

383653981 is a deficient number, since it is larger than the sum of its proper divisors (58719).

383653981 is an equidigital number, since it uses as much as digits as its factorization.

383653981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58718.

The product of its digits is 466560, while the sum is 46.

The square root of 383653981 is about 19587.0870983921. The cubic root of 383653981 is about 726.6298526880.

The spelling of 383653981 in words is "three hundred eighty-three million, six hundred fifty-three thousand, nine hundred eighty-one".