1255643513 has 4 divisors (see below), whose sum is σ = 1255834368. Its totient is φ = 1255452660.

The previous prime is 1255643509. The next prime is 1255643527. The reversal of 1255643513 is 3153465521.

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 1255643513 - 2² = 1255643509 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255643503) 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, 85193 + ... + 98838.

It is an arithmetic number, because the mean of its divisors is an integer number (313958592).

Almost surely, 2^1255643513 is an apocalyptic number.

It is an amenable number.

1255643513 is a deficient number, since it is larger than the sum of its proper divisors (190855).

1255643513 is an equidigital number, since it uses as much as digits as its factorization.

1255643513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190854.

The product of its digits is 54000, while the sum is 35.

The square root of 1255643513 is about 35435.0605050986. The cubic root of 1255643513 is about 1078.8360554218.

The spelling of 1255643513 in words is "one billion, two hundred fifty-five million, six hundred forty-three thousand, five hundred thirteen".