1097815861 has 4 divisors (see below), whose sum is σ = 1103881324. Its totient is φ = 1091750400.

The previous prime is 1097815853. The next prime is 1097815883. The reversal of 1097815861 is 1685187901.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 54848836 + 1042967025 = 7406^2 + 32295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1097815861 - 2³ = 1097815853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1097815361) 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 in 3 ways as a sum of consecutive naturals, for example, 3032460 + ... + 3032821.

It is an arithmetic number, because the mean of its divisors is an integer number (275970331).

Almost surely, 2^1097815861 is an apocalyptic number.

It is an amenable number.

1097815861 is a deficient number, since it is larger than the sum of its proper divisors (6065463).

1097815861 is an equidigital number, since it uses as much as digits as its factorization.

1097815861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6065462.

The product of its (nonzero) digits is 120960, while the sum is 46.

The square root of 1097815861 is about 33133.3044081027. The cubic root of 1097815861 is about 1031.5964375272.

The spelling of 1097815861 in words is "one billion, ninety-seven million, eight hundred fifteen thousand, eight hundred sixty-one".