264139987 has 2 divisors, whose sum is σ = 264139988. Its totient is φ = 264139986.

The previous prime is 264139963. The next prime is 264140029. The reversal of 264139987 is 789931462.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 264139987 - 2¹⁵ = 264107219 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 264139987.

It is not a weakly prime, because it can be changed into another prime (264137987) 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 as a sum of consecutive naturals, namely, 132069993 + 132069994.

It is an arithmetic number, because the mean of its divisors is an integer number (132069994).

Almost surely, 2^264139987 is an apocalyptic number.

264139987 is a deficient number, since it is larger than the sum of its proper divisors (1).

264139987 is an equidigital number, since it uses as much as digits as its factorization.

264139987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The square root of 264139987 is about 16252.3840405031. The cubic root of 264139987 is about 641.6202331123.

The spelling of 264139987 in words is "two hundred sixty-four million, one hundred thirty-nine thousand, nine hundred eighty-seven".