1661766539672 has 8 divisors (see below), whose sum is σ = 3115812261900. Its totient is φ = 830883269832.

The previous prime is 1661766539669. The next prime is 1661766539677. The reversal of 1661766539672 is 2769356671661.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×1661766539672² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1661766539599 and 1661766539608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661766539677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103860408722 + ... + 103860408737.

Almost surely, 2^{1661766539672} is an apocalyptic number.

It is an amenable number.

1661766539672 is a deficient number, since it is larger than the sum of its proper divisors (1454045722228).

1661766539672 is a wasteful number, since it uses less digits than its factorization.

1661766539672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207720817465 (or 207720817461 counting only the distinct ones).

The product of its digits is 102876480, while the sum is 65.

The spelling of 1661766539672 in words is "one trillion, six hundred sixty-one billion, seven hundred sixty-six million, five hundred thirty-nine thousand, six hundred seventy-two".