1561668 has 24 divisors (see below), whose sum is σ = 3669120. Its totient is φ = 516960.

The previous prime is 1561657. The next prime is 1561673. The reversal of 1561668 is 8661651.

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, 1813 + ... + 2531.

It is an arithmetic number, because the mean of its divisors is an integer number (152880).

2^1561668 is an apocalyptic number.

It is an amenable number.

1561668 is an abundant number, since it is smaller than the sum of its proper divisors (2107452).

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

1561668 is a wasteful number, since it uses less digits than its factorization.

1561668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907 (or 905 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 1561668 is about 1249.6671556859. The cubic root of 1561668 is about 116.0191209067.

The spelling of 1561668 in words is "one million, five hundred sixty-one thousand, six hundred sixty-eight".