1957640 has 32 divisors (see below), whose sum is σ = 4455000. Its totient is φ = 774144.

The previous prime is 1957639. The next prime is 1957651. The reversal of 1957640 is 467591.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1779556 + 178084 = 1334^2 + 422^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1957597 and 1957606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4136 + ... + 4584.

2^1957640 is an apocalyptic number.

1957640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1957640 is an abundant number, since it is smaller than the sum of its proper divisors (2497360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1957640 is a wasteful number, since it uses less digits than its factorization.

1957640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569 (or 565 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 1957640 is about 1399.1568889871. The cubic root of 1957640 is about 125.0962458748.

The spelling of 1957640 in words is "one million, nine hundred fifty-seven thousand, six hundred forty".