312499987 has 2 divisors, whose sum is σ = 312499988. Its totient is φ = 312499986.

The previous prime is 312499961. The next prime is 312500017. The reversal of 312499987 is 789994213.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 312499987 - 2¹⁵ = 312467219 is a prime.

It is a zygodrome in base 5.

It is not a weakly prime, because it can be changed into another prime (312499927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156249993 + 156249994.

It is an arithmetic number, because the mean of its divisors is an integer number (156249994).

Almost surely, 2^312499987 is an apocalyptic number.

312499987 is a deficient number, since it is larger than the sum of its proper divisors (1).

312499987 is an equidigital number, since it uses as much as digits as its factorization.

312499987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 52.

The square root of 312499987 is about 17677.6691619682. The cubic root of 312499987 is about 678.6043947387.

It can be divided in two parts, 31249998 and 7, that multiplied together give a triangular number (218749986 = T₂₀₉₁₆).

The spelling of 312499987 in words is "three hundred twelve million, four hundred ninety-nine thousand, nine hundred eighty-seven".