1098091581 has 4 divisors (see below), whose sum is σ = 1464122112. Its totient is φ = 732061052.

The previous prime is 1098091543. The next prime is 1098091601. The reversal of 1098091581 is 1851908901.

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.

It is a cyclic number.

It is not a de Polignac number, because 1098091581 - 2¹⁴ = 1098075197 is a prime.

It is a super-2 number, since 2×1098091581² = 2411610240526159122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1098091531) 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, 183015261 + ... + 183015266.

It is an arithmetic number, because the mean of its divisors is an integer number (366030528).

Almost surely, 2^1098091581 is an apocalyptic number.

It is an amenable number.

1098091581 is a deficient number, since it is larger than the sum of its proper divisors (366030531).

1098091581 is an equidigital number, since it uses as much as digits as its factorization.

1098091581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366030530.

The product of its (nonzero) digits is 25920, while the sum is 42.

The square root of 1098091581 is about 33137.4649151078. The cubic root of 1098091581 is about 1031.6827932241.

The spelling of 1098091581 in words is "one billion, ninety-eight million, ninety-one thousand, five hundred eighty-one".