391997950 has 12 divisors (see below), whose sum is σ = 729116280. Its totient is φ = 156799160.

The previous prime is 391997927. The next prime is 391997971. The reversal of 391997950 is 59799193.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3919930 + ... + 3920029.

It is an arithmetic number, because the mean of its divisors is an integer number (60759690).

Almost surely, 2^391997950 is an apocalyptic number.

391997950 is a deficient number, since it is larger than the sum of its proper divisors (337118330).

391997950 is a wasteful number, since it uses less digits than its factorization.

391997950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7839971 (or 7839966 counting only the distinct ones).

The product of its (nonzero) digits is 688905, while the sum is 52.

The square root of 391997950 is about 19798.9381028377. The cubic root of 391997950 is about 731.8598662240.

The spelling of 391997950 in words is "three hundred ninety-one million, nine hundred ninety-seven thousand, nine hundred fifty".