1557945 has 24 divisors (see below), whose sum is σ = 2737800. Its totient is φ = 819456.

The previous prime is 1557889. The next prime is 1557947. The reversal of 1557945 is 5497551.

It can be written as a sum of positive squares in 4 ways, for example, as 441 + 1557504 = 21^2 + 1248^2 .

It is not a de Polignac number, because 1557945 - 2⁹ = 1557433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1557947) 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 23 ways as a sum of consecutive naturals, for example, 3811 + ... + 4199.

It is an arithmetic number, because the mean of its divisors is an integer number (114075).

2^1557945 is an apocalyptic number.

1557945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1557945 is a deficient number, since it is larger than the sum of its proper divisors (1179855).

1557945 is a wasteful number, since it uses less digits than its factorization.

1557945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 486 counting only the distinct ones).

The product of its digits is 31500, while the sum is 36.

The square root of 1557945 is about 1248.1766701874. The cubic root of 1557945 is about 115.9268514255.

It can be divided in two parts, 155 and 7945, that added together give a square (8100 = 90²).

The spelling of 1557945 in words is "one million, five hundred fifty-seven thousand, nine hundred forty-five".