393961381 has 8 divisors (see below), whose sum is σ = 429984000. Its totient is φ = 357973440.

The previous prime is 393961369. The next prime is 393961429. The reversal of 393961381 is 183169393.

It is a happy number.

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

It is not a de Polignac number, because 393961381 - 2⁹ = 393960869 is a prime.

It is a super-2 number, since 2×393961381² = 310411139438854322, 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 (393961331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18925 + ... + 33853.

It is an arithmetic number, because the mean of its divisors is an integer number (53748000).

Almost surely, 2^393961381 is an apocalyptic number.

It is an amenable number.

393961381 is a deficient number, since it is larger than the sum of its proper divisors (36022619).

393961381 is a wasteful number, since it uses less digits than its factorization.

393961381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17339.

The product of its digits is 104976, while the sum is 43.

The square root of 393961381 is about 19848.4604188839. The cubic root of 393961381 is about 733.0797398404.

The spelling of 393961381 in words is "three hundred ninety-three million, nine hundred sixty-one thousand, three hundred eighty-one".