1265780387 has 2 divisors, whose sum is σ = 1265780388. Its totient is φ = 1265780386.

The previous prime is 1265780381. The next prime is 1265780393. The reversal of 1265780387 is 7830875621.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1265780381) and next prime (1265780393).

It is a cyclic number.

It is not a de Polignac number, because 1265780387 - 2¹⁶ = 1265714851 is a prime.

It is a super-2 number, since 2×1265780387² = 3204399976227739538, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1265780381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632890193 + 632890194.

It is an arithmetic number, because the mean of its divisors is an integer number (632890194).

Almost surely, 2^1265780387 is an apocalyptic number.

1265780387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1265780387 is an equidigital number, since it uses as much as digits as its factorization.

1265780387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 564480, while the sum is 47.

The square root of 1265780387 is about 35577.8075069277. The cubic root of 1265780387 is about 1081.7314439356.

The spelling of 1265780387 in words is "one billion, two hundred sixty-five million, seven hundred eighty thousand, three hundred eighty-seven".