1265063203921 has 24 divisors (see below), whose sum is σ = 1414887516000. Its totient is φ = 1129929134400.

The previous prime is 1265063203897. The next prime is 1265063203939. The reversal of 1265063203921 is 1293023605621.

It is not a de Polignac number, because 1265063203921 - 2³⁵ = 1230703465553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1265063203951) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 12879805 + ... + 12977653.

It is an arithmetic number, because the mean of its divisors is an integer number (58953646500).

Almost surely, 2^{1265063203921} is an apocalyptic number.

1265063203921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1265063203921 is a deficient number, since it is larger than the sum of its proper divisors (149824312079).

1265063203921 is a wasteful number, since it uses less digits than its factorization.

1265063203921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99741 (or 99730 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 40.

The spelling of 1265063203921 in words is "one trillion, two hundred sixty-five billion, sixty-three million, two hundred three thousand, nine hundred twenty-one".