1897649618 has 6 divisors (see below), whose sum is σ = 2846566839. Its totient is φ = 948794006.

The previous prime is 1897649603. The next prime is 1897649639. The reversal of 1897649618 is 8169467981.

It can be written as a sum of positive squares in only one way, i.e., 948824809 + 948824809 = 30803^2 + 30803^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=30803.

It is a Duffinian number.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 46205 + ... + 77007.

Almost surely, 2^1897649618 is an apocalyptic number.

1897649618 is a deficient number, since it is larger than the sum of its proper divisors (948917221).

1897649618 is an frugal number, since it uses more digits than its factorization.

1897649618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61608 (or 30805 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 59.

The square root of 1897649618 is about 43562.0203617784. The cubic root of 1897649618 is about 1238.0514005399.

The spelling of 1897649618 in words is "one billion, eight hundred ninety-seven million, six hundred forty-nine thousand, six hundred eighteen".