511261987 has 2 divisors, whose sum is σ = 511261988. Its totient is φ = 511261986.

The previous prime is 511261981. The next prime is 511261999. The reversal of 511261987 is 789162115.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 511261987 - 2¹⁹ = 510737699 is a prime.

It is a super-2 number, since 2×511261987² = 522777638702376338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (511261981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255630993 + 255630994.

It is an arithmetic number, because the mean of its divisors is an integer number (255630994).

Almost surely, 2^511261987 is an apocalyptic number.

511261987 is a deficient number, since it is larger than the sum of its proper divisors (1).

511261987 is an equidigital number, since it uses as much as digits as its factorization.

511261987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 40.

The square root of 511261987 is about 22611.1031796328. The cubic root of 511261987 is about 799.6154333944.

The spelling of 511261987 in words is "five hundred eleven million, two hundred sixty-one thousand, nine hundred eighty-seven".