393509421 has 20 divisors (see below), whose sum is σ = 622415772. Its totient is φ = 246907008.

The previous prime is 393509401. The next prime is 393509429. The reversal of 393509421 is 124905393.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 122544900 + 270964521 = 11070^2 + 16461^2 .

It is not a de Polignac number, because 393509421 - 2⁶ = 393509357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393509429) 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 19 ways as a sum of consecutive naturals, for example, 141510 + ... + 144263.

Almost surely, 2^393509421 is an apocalyptic number.

It is an amenable number.

393509421 is a deficient number, since it is larger than the sum of its proper divisors (228906351).

393509421 is a wasteful number, since it uses less digits than its factorization.

393509421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285802 (or 285793 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 393509421 is about 19837.0718857396. The cubic root of 393509421 is about 732.7992982236.

The spelling of 393509421 in words is "three hundred ninety-three million, five hundred nine thousand, four hundred twenty-one".