391285428 has 12 divisors (see below), whose sum is σ = 912999360. Its totient is φ = 130428472.

The previous prime is 391285421. The next prime is 391285451. The reversal of 391285428 is 824582193.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 391285428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391285421) 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, 16303548 + ... + 16303571.

It is an arithmetic number, because the mean of its divisors is an integer number (76083280).

Almost surely, 2^391285428 is an apocalyptic number.

It is an amenable number.

391285428 is an abundant number, since it is smaller than the sum of its proper divisors (521713932).

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

391285428 is a wasteful number, since it uses less digits than its factorization.

391285428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32607126 (or 32607124 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 391285428 is about 19780.9359738107. The cubic root of 391285428 is about 731.4161712797.

The spelling of 391285428 in words is "three hundred ninety-one million, two hundred eighty-five thousand, four hundred twenty-eight".