1997766564361 has 16 divisors (see below), whose sum is σ = 2043045222400. Its totient is φ = 1952994230928.

The previous prime is 1997766564257. The next prime is 1997766564397. The reversal of 1997766564361 is 1634656677991.

It is a cyclic number.

It is not a de Polignac number, because 1997766564361 - 2²⁹ = 1997229693449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1997766564961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57161230 + ... + 57196168.

It is an arithmetic number, because the mean of its divisors is an integer number (127690326400).

Almost surely, 2^{1997766564361} is an apocalyptic number.

It is an amenable number.

1997766564361 is a deficient number, since it is larger than the sum of its proper divisors (45278658039).

1997766564361 is a wasteful number, since it uses less digits than its factorization.

1997766564361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42148.

The product of its digits is 308629440, while the sum is 70.

The spelling of 1997766564361 in words is "one trillion, nine hundred ninety-seven billion, seven hundred sixty-six million, five hundred sixty-four thousand, three hundred sixty-one".