2557729381 has 4 divisors (see below), whose sum is σ = 2574895500. Its totient is φ = 2540563264.

The previous prime is 2557729351. The next prime is 2557729387. The reversal of 2557729381 is 1839277552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1303932100 + 1253797281 = 36110^2 + 35409^2 .

It is a cyclic number.

It is not a de Polignac number, because 2557729381 - 2⁷ = 2557729253 is a prime.

It is a super-2 number, since 2×2557729381² = 13083959172861286322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2557729387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8582836 + ... + 8583133.

It is an arithmetic number, because the mean of its divisors is an integer number (643723875).

Almost surely, 2^2557729381 is an apocalyptic number.

It is an amenable number.

2557729381 is a deficient number, since it is larger than the sum of its proper divisors (17166119).

2557729381 is a wasteful number, since it uses less digits than its factorization.

2557729381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17166118.

The product of its digits is 1058400, while the sum is 49.

The square root of 2557729381 is about 50573.9990607822. Note that the first 3 decimals coincide. The cubic root of 2557729381 is about 1367.5761893856.

The spelling of 2557729381 in words is "two billion, five hundred fifty-seven million, seven hundred twenty-nine thousand, three hundred eighty-one".