1668536556 has 24 divisors (see below), whose sum is σ = 3908769984. Its totient is φ = 553962000.

The previous prime is 1668536537. The next prime is 1668536557. The reversal of 1668536556 is 6556358661.

It is a happy number.

It is a super-2 number, since 2×1668536556² = 5568028477416682272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1668536499 and 1668536508.

It is not an unprimeable number, because it can be changed into a prime (1668536557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273970 + ... + 279993.

It is an arithmetic number, because the mean of its divisors is an integer number (162865416).

Almost surely, 2^1668536556 is an apocalyptic number.

It is an amenable number.

1668536556 is an abundant number, since it is smaller than the sum of its proper divisors (2240233428).

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

1668536556 is a wasteful number, since it uses less digits than its factorization.

1668536556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554221 (or 554219 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 51.

The square root of 1668536556 is about 40847.7240002427. The cubic root of 1668536556 is about 1186.0743355683.

The spelling of 1668536556 in words is "one billion, six hundred sixty-eight million, five hundred thirty-six thousand, five hundred fifty-six".