1098891 has 6 divisors (see below), whose sum is σ = 1587300. Its totient is φ = 732588.

The previous prime is 1098847. The next prime is 1098953. The reversal of 1098891 is 1988901.

It is not a de Polignac number, because 1098891 - 2⁹ = 1098379 is a prime.

It is a super-2 number, since 2×1098891² = 2415122859762, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1098821) 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, 61041 + ... + 61058.

It is an arithmetic number, because the mean of its divisors is an integer number (264550).

2^1098891 is an apocalyptic number.

1098891 is a deficient number, since it is larger than the sum of its proper divisors (488409).

1098891 is a wasteful number, since it uses less digits than its factorization.

1098891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122105 (or 122102 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 1098891 is about 1048.2800198420. The cubic root of 1098891 is about 103.1933090127.

The spelling of 1098891 in words is "one million, ninety-eight thousand, eight hundred ninety-one".