1668542646650 has 144 divisors (see below), whose sum is σ = 3617714310840. Its totient is φ = 570138624000.

The previous prime is 1668542646629. The next prime is 1668542646671. The reversal of 1668542646650 is 566462458661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1668542646629) and next prime (1668542646671).

It can be written as a sum of positive squares in 12 ways, for example, as 668896615321 + 999646031329 = 817861^2 + 999823^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1668542646650.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 65914196 + ... + 65939504.

Almost surely, 2^{1668542646650} is an apocalyptic number.

1668542646650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1668542646650 is an abundant number, since it is smaller than the sum of its proper divisors (1949171664190).

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

1668542646650 is a wasteful number, since it uses less digits than its factorization.

1668542646650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26001 (or 25985 counting only the distinct ones).

The product of its (nonzero) digits is 49766400, while the sum is 59.

The spelling of 1668542646650 in words is "one trillion, six hundred sixty-eight billion, five hundred forty-two million, six hundred forty-six thousand, six hundred fifty".