1997881769 has 16 divisors (see below), whose sum is σ = 2351623680. Its totient is φ = 1679719680.

The previous prime is 1997881751. The next prime is 1997881771. The reversal of 1997881769 is 9671887991.

It is a de Polignac number, because none of the positive numbers 2^k-1997881769 is a prime.

It is a super-3 number, since 3×1997881769³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1997881789) 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, 138959 + ... + 152660.

It is an arithmetic number, because the mean of its divisors is an integer number (146976480).

Almost surely, 2^1997881769 is an apocalyptic number.

It is an amenable number.

1997881769 is a deficient number, since it is larger than the sum of its proper divisors (353741911).

1997881769 is a wasteful number, since it uses less digits than its factorization.

1997881769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291680.

The product of its digits is 13716864, while the sum is 65.

The square root of 1997881769 is about 44697.6707334957. The cubic root of 1997881769 is about 1259.4760921331.

The spelling of 1997881769 in words is "one billion, nine hundred ninety-seven million, eight hundred eighty-one thousand, seven hundred sixty-nine".