1797920989 has 6 divisors (see below), whose sum is σ = 1802232926. Its totient is φ = 1793613240.

The previous prime is 1797920977. The next prime is 1797921019. The reversal of 1797920989 is 9890297971.

It can be written as a sum of positive squares in only one way, i.e., 1465588089 + 332332900 = 38283^2 + 18230^2 .

It is not a de Polignac number, because 1797920989 - 2¹⁵ = 1797888221 is a prime.

It is a super-3 number, since 3×1797920989³ (a number of 29 digits) contains 333 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 (1797320989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 985332 + ... + 987154.

Almost surely, 2^1797920989 is an apocalyptic number.

It is an amenable number.

1797920989 is a deficient number, since it is larger than the sum of its proper divisors (4311937).

1797920989 is an frugal number, since it uses more digits than its factorization.

1797920989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4187 (or 2364 counting only the distinct ones).

The product of its (nonzero) digits is 5143824, while the sum is 61.

The square root of 1797920989 is about 42401.8984126890. The cubic root of 1797920989 is about 1215.9718866585.

The spelling of 1797920989 in words is "one billion, seven hundred ninety-seven million, nine hundred twenty thousand, nine hundred eighty-nine".