1666672003521 has 64 divisors (see below), whose sum is σ = 2869370634240. Its totient is φ = 936368838720.

The previous prime is 1666672003501. The next prime is 1666672003537. The reversal of 1666672003521 is 1253002766661.

It is not a de Polignac number, because 1666672003521 - 2¹⁵ = 1666671970753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666672003501) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 27904936 + ... + 27964598.

It is an arithmetic number, because the mean of its divisors is an integer number (44833916160).

Almost surely, 2^{1666672003521} is an apocalyptic number.

It is an amenable number.

1666672003521 is a deficient number, since it is larger than the sum of its proper divisors (1202698630719).

1666672003521 is a wasteful number, since it uses less digits than its factorization.

1666672003521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62163 (or 62157 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 1666672003521 in words is "one trillion, six hundred sixty-six billion, six hundred seventy-two million, three thousand, five hundred twenty-one".