1365256121 has 4 divisors (see below), whose sum is σ = 1378015632. Its totient is φ = 1352496612.

The previous prime is 1365256021. The next prime is 1365256129. The reversal of 1365256121 is 1216525631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1365256121 - 2¹⁸ = 1364993977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1365256129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6379595 + ... + 6379808.

It is an arithmetic number, because the mean of its divisors is an integer number (344503908).

Almost surely, 2^1365256121 is an apocalyptic number.

It is an amenable number.

1365256121 is a deficient number, since it is larger than the sum of its proper divisors (12759511).

1365256121 is a wasteful number, since it uses less digits than its factorization.

1365256121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12759510.

The product of its digits is 10800, while the sum is 32.

The square root of 1365256121 is about 36949.3724033305. The cubic root of 1365256121 is about 1109.3571260504.

The spelling of 1365256121 in words is "one billion, three hundred sixty-five million, two hundred fifty-six thousand, one hundred twenty-one".