1098239921 has 2 divisors, whose sum is σ = 1098239922. Its totient is φ = 1098239920.

The previous prime is 1098239911. The next prime is 1098240037. The reversal of 1098239921 is 1299328901.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 747202225 + 351037696 = 27335^2 + 18736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1098239921 is a prime.

It is a super-2 number, since 2×1098239921² = 2412261848156172482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1098239911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 549119960 + 549119961.

It is an arithmetic number, because the mean of its divisors is an integer number (549119961).

Almost surely, 2^1098239921 is an apocalyptic number.

It is an amenable number.

1098239921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1098239921 is an equidigital number, since it uses as much as digits as its factorization.

1098239921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 1098239921 is about 33139.7030916090. The cubic root of 1098239921 is about 1031.7292474353.

The spelling of 1098239921 in words is "one billion, ninety-eight million, two hundred thirty-nine thousand, nine hundred twenty-one".