1098000091 has 4 divisors (see below), whose sum is σ = 1098070384. Its totient is φ = 1097929800.

The previous prime is 1098000073. The next prime is 1098000107. The reversal of 1098000091 is 1900008901.

1098000091 is a nontrivial binomial coefficient, being equal to C(46862, 2).

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1900008901 = 7 ⋅271429843.

It is a 3-Lehmer number, since φ(1098000091) divides (1098000091-1)³.

It is a cyclic number.

It is not a de Polignac number, because 1098000091 - 2⁹ = 1097999579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1098000011) 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, 1 + ... + 46861.

It is an arithmetic number, because the mean of its divisors is an integer number (274517596).

Almost surely, 2^1098000091 is an apocalyptic number.

1098000091 is the 46861-st triangular number and also the 23431-st hexagonal number.

1098000091 is the 15621-st centered nonagonal number.

1098000091 is a deficient number, since it is larger than the sum of its proper divisors (70293).

1098000091 is an equidigital number, since it uses as much as digits as its factorization.

1098000091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70292.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 1098000091 is about 33136.0844246872. The cubic root of 1098000091 is about 1031.6541400947.

Adding to 1098000091 its reverse (1900008901), we get a palindrome (2998008992).

The spelling of 1098000091 in words is "one billion, ninety-eight million, ninety-one", and thus it is an aban number and an uban number.