1998765897 has 8 divisors (see below), whose sum is σ = 2669895456. Its totient is φ = 1330073472.

The previous prime is 1998765893. The next prime is 1998765919. The reversal of 1998765897 is 7985678991.

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

It is not a de Polignac number, because 1998765897 - 2² = 1998765893 is a prime.

It is a super-2 number, since 2×1998765897² = 7990130222020429218, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1998765893) 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, 607368 + ... + 610649.

It is an arithmetic number, because the mean of its divisors is an integer number (333736932).

Almost surely, 2^1998765897 is an apocalyptic number.

It is an amenable number.

1998765897 is a deficient number, since it is larger than the sum of its proper divisors (671129559).

1998765897 is a wasteful number, since it uses less digits than its factorization.

1998765897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1218567.

The product of its digits is 68584320, while the sum is 69.

The square root of 1998765897 is about 44707.5597298712. The cubic root of 1998765897 is about 1259.6618511833.

The spelling of 1998765897 in words is "one billion, nine hundred ninety-eight million, seven hundred sixty-five thousand, eight hundred ninety-seven".