1098023521 has 4 divisors (see below), whose sum is σ = 1254884032. Its totient is φ = 941163012.

The previous prime is 1098023477. The next prime is 1098023543. The reversal of 1098023521 is 1253208901.

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: 1253208901 = 7 ⋅179029843.

It is a cyclic number.

It is not a de Polignac number, because 1098023521 - 2¹⁷ = 1097892449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1098023021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78430245 + ... + 78430258.

It is an arithmetic number, because the mean of its divisors is an integer number (313721008).

Almost surely, 2^1098023521 is an apocalyptic number.

It is an amenable number.

1098023521 is a deficient number, since it is larger than the sum of its proper divisors (156860511).

1098023521 is an equidigital number, since it uses as much as digits as its factorization.

1098023521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156860510.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1098023521 is about 33136.4379648749. The cubic root of 1098023521 is about 1031.6614781283.

The spelling of 1098023521 in words is "one billion, ninety-eight million, twenty-three thousand, five hundred twenty-one".