391780240 has 40 divisors (see below), whose sum is σ = 928085688. Its totient is φ = 153753600.

The previous prime is 391780231. The next prime is 391780241. The reversal of 391780240 is 42087193.

It can be written as a sum of positive squares in 4 ways, for example, as 149915536 + 241864704 = 12244^2 + 15552^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 391780196 and 391780205.

It is not an unprimeable number, because it can be changed into a prime (391780241) 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, 41961 + ... + 50440.

Almost surely, 2^391780240 is an apocalyptic number.

It is an amenable number.

391780240 is an abundant number, since it is smaller than the sum of its proper divisors (536305448).

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

391780240 is a wasteful number, since it uses less digits than its factorization.

391780240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92467 (or 92461 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 391780240 is about 19793.4393171071. The cubic root of 391780240 is about 731.7243530003.

The spelling of 391780240 in words is "three hundred ninety-one million, seven hundred eighty thousand, two hundred forty".