1985657 has 4 divisors (see below), whose sum is σ = 2013696. Its totient is φ = 1957620.

The previous prime is 1985639. The next prime is 1985663. The reversal of 1985657 is 7565891.

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 a cyclic number.

It is not a de Polignac number, because 1985657 - 2⁶ = 1985593 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 (1985677) 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, 13913 + ... + 14054.

It is an arithmetic number, because the mean of its divisors is an integer number (503424).

2^1985657 is an apocalyptic number.

It is an amenable number.

1985657 is a deficient number, since it is larger than the sum of its proper divisors (28039).

1985657 is an equidigital number, since it uses as much as digits as its factorization.

1985657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28038.

The product of its digits is 75600, while the sum is 41.

The square root of 1985657 is about 1409.1334216461. The cubic root of 1985657 is about 125.6901979995.

The spelling of 1985657 in words is "one million, nine hundred eighty-five thousand, six hundred fifty-seven".