391531063 has 16 divisors (see below), whose sum is σ = 516858624. Its totient is φ = 287141760.

The previous prime is 391531057. The next prime is 391531079. The reversal of 391531063 is 360135193.

It is a cyclic number.

It is not a de Polignac number, because 391531063 - 2¹⁷ = 391399991 is a prime.

It is a super-4 number, since 4×391531063⁴ (a number of 35 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391531033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148245 + ... + 150862.

It is an arithmetic number, because the mean of its divisors is an integer number (32303664).

Almost surely, 2^391531063 is an apocalyptic number.

391531063 is a deficient number, since it is larger than the sum of its proper divisors (125327561).

391531063 is a wasteful number, since it uses less digits than its factorization.

391531063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299142.

The product of its (nonzero) digits is 7290, while the sum is 31.

The square root of 391531063 is about 19787.1438818239. The cubic root of 391531063 is about 731.5691915700.

The spelling of 391531063 in words is "three hundred ninety-one million, five hundred thirty-one thousand, sixty-three".