394421520 has 40 divisors (see below), whose sum is σ = 1222707456. Its totient is φ = 105179008.

The previous prime is 394421501. The next prime is 394421527. The reversal of 394421520 is 25124493.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×394421520² = 311136670878220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (394421527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 821472 + ... + 821951.

Almost surely, 2^394421520 is an apocalyptic number.

394421520 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

394421520 is an abundant number, since it is smaller than the sum of its proper divisors (828285936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

394421520 is a wasteful number, since it uses less digits than its factorization.

394421520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643439 (or 1643433 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 394421520 is about 19860.0483383098. The cubic root of 394421520 is about 733.3650362786.

The spelling of 394421520 in words is "three hundred ninety-four million, four hundred twenty-one thousand, five hundred twenty".