1660554561 has 12 divisors (see below), whose sum is σ = 2275535472. Its totient is φ = 1077113808.

The previous prime is 1660554557. The next prime is 1660554563. The reversal of 1660554561 is 1654550661.

It is not a de Polignac number, because 1660554561 - 2² = 1660554557 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1660554563) 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, 198055 + ... + 206268.

It is an arithmetic number, because the mean of its divisors is an integer number (189627956).

Almost surely, 2^1660554561 is an apocalyptic number.

It is an amenable number.

1660554561 is a deficient number, since it is larger than the sum of its proper divisors (614980911).

1660554561 is an equidigital number, since it uses as much as digits as its factorization.

1660554561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404400 (or 404363 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 39.

The square root of 1660554561 is about 40749.9025888406. The cubic root of 1660554561 is about 1184.1799856589.

The spelling of 1660554561 in words is "one billion, six hundred sixty million, five hundred fifty-four thousand, five hundred sixty-one".