1265401155 has 16 divisors (see below), whose sum is σ = 2026725120. Its totient is φ = 674186208.

The previous prime is 1265401133. The next prime is 1265401187. The reversal of 1265401155 is 5511045621.

It is not a de Polignac number, because 1265401155 - 2⁶ = 1265401091 is a prime.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 28165 + ... + 57654.

It is an arithmetic number, because the mean of its divisors is an integer number (126670320).

Almost surely, 2^1265401155 is an apocalyptic number.

1265401155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1265401155 is a deficient number, since it is larger than the sum of its proper divisors (761323965).

1265401155 is an equidigital number, since it uses as much as digits as its factorization.

1265401155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86810.

The product of its (nonzero) digits is 6000, while the sum is 30.

The square root of 1265401155 is about 35572.4774931407. The cubic root of 1265401155 is about 1081.6234030362.

Adding to 1265401155 its reverse (5511045621), we get a palindrome (6776446776).

The spelling of 1265401155 in words is "one billion, two hundred sixty-five million, four hundred one thousand, one hundred fifty-five".