2102809557 has 4 divisors (see below), whose sum is σ = 2803746080. Its totient is φ = 1401873036.

The previous prime is 2102809531. The next prime is 2102809559. The reversal of 2102809557 is 7559082012.

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 not a de Polignac number, because 2102809557 - 2¹⁵ = 2102776789 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 (2102809559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350468257 + ... + 350468262.

It is an arithmetic number, because the mean of its divisors is an integer number (700936520).

Almost surely, 2^2102809557 is an apocalyptic number.

It is an amenable number.

2102809557 is a deficient number, since it is larger than the sum of its proper divisors (700936523).

2102809557 is an equidigital number, since it uses as much as digits as its factorization.

2102809557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700936522.

The product of its (nonzero) digits is 50400, while the sum is 39.

The square root of 2102809557 is about 45856.4014833262. The cubic root of 2102809557 is about 1281.1499994068.

The spelling of 2102809557 in words is "two billion, one hundred two million, eight hundred nine thousand, five hundred fifty-seven".