506999991 has 4 divisors (see below), whose sum is σ = 675999992. Its totient is φ = 337999992.

The previous prime is 506999957. The next prime is 507000001. The reversal of 506999991 is 199999605.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 506999991 - 2²² = 502805687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (506999191) 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, 84499996 + ... + 84500001.

It is an arithmetic number, because the mean of its divisors is an integer number (168999998).

Almost surely, 2^506999991 is an apocalyptic number.

506999991 is a deficient number, since it is larger than the sum of its proper divisors (169000001).

506999991 is a wasteful number, since it uses less digits than its factorization.

506999991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169000000.

The product of its (nonzero) digits is 1771470, while the sum is 57.

The square root of 506999991 is about 22516.6602985434. The cubic root of 506999991 is about 797.3873052172.

The spelling of 506999991 in words is "five hundred six million, nine hundred ninety-nine thousand, nine hundred ninety-one".