393676981 has 4 divisors (see below), whose sum is σ = 400130764. Its totient is φ = 387223200.

The previous prime is 393676937. The next prime is 393676999. The reversal of 393676981 is 189676393.

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 82719025 + 310957956 = 9095^2 + 17634^2 .

It is a cyclic number.

It is not a de Polignac number, because 393676981 - 2¹⁵ = 393644213 is a prime.

It is a super-2 number, since 2×393676981² = 309963130738548722, 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 (393676931) 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, 3226800 + ... + 3226921.

It is an arithmetic number, because the mean of its divisors is an integer number (100032691).

Almost surely, 2^393676981 is an apocalyptic number.

It is an amenable number.

393676981 is a deficient number, since it is larger than the sum of its proper divisors (6453783).

393676981 is an equidigital number, since it uses as much as digits as its factorization.

393676981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6453782.

The product of its digits is 1469664, while the sum is 52.

The square root of 393676981 is about 19841.2948418192. The cubic root of 393676981 is about 732.9032944008.

The spelling of 393676981 in words is "three hundred ninety-three million, six hundred seventy-six thousand, nine hundred eighty-one".