1280039687 has 2 divisors, whose sum is σ = 1280039688. Its totient is φ = 1280039686.

The previous prime is 1280039627. The next prime is 1280039699. The reversal of 1280039687 is 7869300821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1280039687 - 2¹⁶ = 1279974151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1280039627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640019843 + 640019844.

It is an arithmetic number, because the mean of its divisors is an integer number (640019844).

Almost surely, 2^1280039687 is an apocalyptic number.

1280039687 is a deficient number, since it is larger than the sum of its proper divisors (1).

1280039687 is an equidigital number, since it uses as much as digits as its factorization.

1280039687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 1280039687 is about 35777.6422783839. The cubic root of 1280039687 is about 1085.7782680941.

The spelling of 1280039687 in words is "one billion, two hundred eighty million, thirty-nine thousand, six hundred eighty-seven".