1252805509 has 4 divisors (see below), whose sum is σ = 1258324704. Its totient is φ = 1247286316.

The previous prime is 1252805503. The next prime is 1252805549. The reversal of 1252805509 is 9055082521.

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 a de Polignac number, because none of the positive numbers 2^k-1252805509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1252805503) 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, 2759257 + ... + 2759710.

It is an arithmetic number, because the mean of its divisors is an integer number (314581176).

Almost surely, 2^1252805509 is an apocalyptic number.

It is an amenable number.

1252805509 is a deficient number, since it is larger than the sum of its proper divisors (5519195).

1252805509 is an equidigital number, since it uses as much as digits as its factorization.

1252805509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5519194.

The product of its (nonzero) digits is 36000, while the sum is 37.

The square root of 1252805509 is about 35394.9927108341. The cubic root of 1252805509 is about 1078.0226476288.

The spelling of 1252805509 in words is "one billion, two hundred fifty-two million, eight hundred five thousand, five hundred nine".