1997616753661 has 8 divisors (see below), whose sum is σ = 2031632638560. Its totient is φ = 1963606134672.

The previous prime is 1997616753653. The next prime is 1997616753677. The reversal of 1997616753661 is 1663576167991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1997616753661 - 2³ = 1997616753653 is a prime.

It is a super-2 number, since 2×1997616753661² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997616753631) 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, 547530 + ... + 2072443.

It is an arithmetic number, because the mean of its divisors is an integer number (253954079820).

Almost surely, 2^{1997616753661} is an apocalyptic number.

It is an amenable number.

1997616753661 is a deficient number, since it is larger than the sum of its proper divisors (34015884899).

1997616753661 is a wasteful number, since it uses less digits than its factorization.

1997616753661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2632955.

The product of its digits is 77157360, while the sum is 67.

The spelling of 1997616753661 in words is "one trillion, nine hundred ninety-seven billion, six hundred sixteen million, seven hundred fifty-three thousand, six hundred sixty-one".