1098815857 has 2 divisors, whose sum is σ = 1098815858. Its totient is φ = 1098815856.

The previous prime is 1098815843. The next prime is 1098815881. The reversal of 1098815857 is 7585188901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 919363041 + 179452816 = 30321^2 + 13396^2 .

It is a cyclic number.

It is not a de Polignac number, because 1098815857 - 2²³ = 1090427249 is a prime.

It is not a weakly prime, because it can be changed into another prime (1098815807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 549407928 + 549407929.

It is an arithmetic number, because the mean of its divisors is an integer number (549407929).

Almost surely, 2^1098815857 is an apocalyptic number.

It is an amenable number.

1098815857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1098815857 is an equidigital number, since it uses as much as digits as its factorization.

1098815857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 806400, while the sum is 52.

The square root of 1098815857 is about 33148.3914692704. The cubic root of 1098815857 is about 1031.9095681355.

The spelling of 1098815857 in words is "one billion, ninety-eight million, eight hundred fifteen thousand, eight hundred fifty-seven".