1098237561 has 4 divisors (see below), whose sum is σ = 1464316752. Its totient is φ = 732158372.

The previous prime is 1098237559. The next prime is 1098237599. The reversal of 1098237561 is 1657328901.

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 1098237561 - 2¹ = 1098237559 is a prime.

It is a super-2 number, since 2×1098237561² = 2412251480782457442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1098237551) 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, 183039591 + ... + 183039596.

It is an arithmetic number, because the mean of its divisors is an integer number (366079188).

Almost surely, 2^1098237561 is an apocalyptic number.

It is an amenable number.

1098237561 is a deficient number, since it is larger than the sum of its proper divisors (366079191).

1098237561 is an equidigital number, since it uses as much as digits as its factorization.

1098237561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366079190.

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 1098237561 is about 33139.6674847531. The cubic root of 1098237561 is about 1031.7285084095.

The spelling of 1098237561 in words is "one billion, ninety-eight million, two hundred thirty-seven thousand, five hundred sixty-one".