1098866989 has 4 divisors (see below), whose sum is σ = 1198764000. Its totient is φ = 998969980.

The previous prime is 1098866981. The next prime is 1098867001. The reversal of 1098866989 is 9896688901.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9896688901 = 11 ⋅899698991.

It is a cyclic number.

It is not a de Polignac number, because 1098866989 - 2³ = 1098866981 is a prime.

It is a super-2 number, since 2×1098866989² = 2415017319027852242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1098866989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1098866981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49948489 + ... + 49948510.

It is an arithmetic number, because the mean of its divisors is an integer number (299691000).

Almost surely, 2^1098866989 is an apocalyptic number.

It is an amenable number.

1098866989 is a deficient number, since it is larger than the sum of its proper divisors (99897011).

1098866989 is an equidigital number, since it uses as much as digits as its factorization.

1098866989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99897010.

The product of its (nonzero) digits is 13436928, while the sum is 64.

The square root of 1098866989 is about 33149.1627194413. The cubic root of 1098866989 is about 1031.9255740875.

It can be divided in two parts, 10988 and 66989, that added together give a palindrome (77977).

The spelling of 1098866989 in words is "one billion, ninety-eight million, eight hundred sixty-six thousand, nine hundred eighty-nine".