1891252809 has 12 divisors (see below), whose sum is σ = 2850584256. Its totient is φ = 1206016152.

The previous prime is 1891252757. The next prime is 1891252819. The reversal of 1891252809 is 9082521981.

It is not a de Polignac number, because 1891252809 - 2¹¹ = 1891250761 is a prime.

It is a super-3 number, since 3×1891252809³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1891252819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4568037 + ... + 4568450.

It is an arithmetic number, because the mean of its divisors is an integer number (237548688).

Almost surely, 2^1891252809 is an apocalyptic number.

It is an amenable number.

1891252809 is a deficient number, since it is larger than the sum of its proper divisors (959331447).

1891252809 is a wasteful number, since it uses less digits than its factorization.

1891252809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9136516 (or 9136513 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 1891252809 is about 43488.5365240083. The cubic root of 1891252809 is about 1236.6587139060.

The spelling of 1891252809 in words is "one billion, eight hundred ninety-one million, two hundred fifty-two thousand, eight hundred nine".