511026991 has 4 divisors (see below), whose sum is σ = 511257672. Its totient is φ = 510796312.

The previous prime is 511026979. The next prime is 511027001. The reversal of 511026991 is 199620115.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 511026991 - 2⁵ = 511026959 is a prime.

It is a super-2 number, since 2×511026991² = 522297171061028162, which contains 22 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 (511024991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111985 + ... + 116458.

It is an arithmetic number, because the mean of its divisors is an integer number (127814418).

Almost surely, 2^511026991 is an apocalyptic number.

511026991 is a deficient number, since it is larger than the sum of its proper divisors (230681).

511026991 is a wasteful number, since it uses less digits than its factorization.

511026991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230680.

The product of its (nonzero) digits is 4860, while the sum is 34.

The square root of 511026991 is about 22605.9061088026. The cubic root of 511026991 is about 799.4929031130.

The spelling of 511026991 in words is "five hundred eleven million, twenty-six thousand, nine hundred ninety-one".