506947991 has 32 divisors (see below), whose sum is σ = 602173440. Its totient is φ = 421977600.

The previous prime is 506947979. The next prime is 506947999. The reversal of 506947991 is 199749605.

It is a de Polignac number, because none of the positive numbers 2^k-506947991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (506947999) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 854591 + ... + 855183.

It is an arithmetic number, because the mean of its divisors is an integer number (18817920).

Almost surely, 2^506947991 is an apocalyptic number.

506947991 is a deficient number, since it is larger than the sum of its proper divisors (95225449).

506947991 is a wasteful number, since it uses less digits than its factorization.

506947991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767.

The product of its (nonzero) digits is 612360, while the sum is 50.

The square root of 506947991 is about 22515.5055683855. The cubic root of 506947991 is about 797.3600431802.

It can be divided in two parts, 50694 and 7991, that added together give a palindrome (58685).

The spelling of 506947991 in words is "five hundred six million, nine hundred forty-seven thousand, nine hundred ninety-one".