2091557 has 8 divisors (see below), whose sum is σ = 2263800. Its totient is φ = 1920960.

The previous prime is 2091553. The next prime is 2091581. The reversal of 2091557 is 7551902.

It can be written as a sum of positive squares in 4 ways, for example, as 106276 + 1985281 = 326^2 + 1409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2091557 - 2² = 2091553 is a prime.

It is a super-2 number, since 2×2091557² = 8749221368498, 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 (2091553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4307 + ... + 4767.

It is an arithmetic number, because the mean of its divisors is an integer number (282975).

2^2091557 is an apocalyptic number.

It is an amenable number.

2091557 is a deficient number, since it is larger than the sum of its proper divisors (172243).

2091557 is a wasteful number, since it uses less digits than its factorization.

2091557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823.

The product of its (nonzero) digits is 3150, while the sum is 29.

The square root of 2091557 is about 1446.2216289352. The cubic root of 2091557 is about 127.8860680536.

The spelling of 2091557 in words is "two million, ninety-one thousand, five hundred fifty-seven".