1090685257 has 4 divisors (see below), whose sum is σ = 1090772676. Its totient is φ = 1090597840.

The previous prime is 1090685227. The next prime is 1090685261. The reversal of 1090685257 is 7525860901.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 452668176 + 638017081 = 21276^2 + 25259^2 .

It is a cyclic number.

It is not a de Polignac number, because 1090685257 - 2²⁷ = 956467529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1090685227) 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, 21094 + ... + 51247.

It is an arithmetic number, because the mean of its divisors is an integer number (272693169).

Almost surely, 2^1090685257 is an apocalyptic number.

It is an amenable number.

1090685257 is a deficient number, since it is larger than the sum of its proper divisors (87419).

1090685257 is an equidigital number, since it uses as much as digits as its factorization.

1090685257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87418.

The product of its (nonzero) digits is 151200, while the sum is 43.

The square root of 1090685257 is about 33025.5243258907. The cubic root of 1090685257 is about 1029.3580871661.

The spelling of 1090685257 in words is "one billion, ninety million, six hundred eighty-five thousand, two hundred fifty-seven".