1557666 has 24 divisors (see below), whose sum is σ = 3682224. Its totient is φ = 471960.

The previous prime is 1557653. The next prime is 1557667. The reversal of 1557666 is 6667551.

It is a happy number.

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1557666.

It is not an unprimeable number, because it can be changed into a prime (1557667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3736 + ... + 4131.

It is an arithmetic number, because the mean of its divisors is an integer number (153426).

2^1557666 is an apocalyptic number.

1557666 is an abundant number, since it is smaller than the sum of its proper divisors (2124558).

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

1557666 is a wasteful number, since it uses less digits than its factorization.

1557666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7886 (or 7883 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 1557666 is about 1248.0649021585. The cubic root of 1557666 is about 115.9199308725.

The spelling of 1557666 in words is "one million, five hundred fifty-seven thousand, six hundred sixty-six".