1981897375 has 16 divisors (see below), whose sum is σ = 2475716256. Its totient is φ = 1584038400.

The previous prime is 1981897369. The next prime is 1981897399. The reversal of 1981897375 is 5737981891.

It is not a de Polignac number, because 1981897375 - 2¹⁹ = 1981373087 is a prime.

It is a Duffinian number.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 138559 + ... + 152191.

It is an arithmetic number, because the mean of its divisors is an integer number (154732266).

Almost surely, 2^1981897375 is an apocalyptic number.

1981897375 is a deficient number, since it is larger than the sum of its proper divisors (493818881).

1981897375 is a wasteful number, since it uses less digits than its factorization.

1981897375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14811 (or 14801 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 58.

The square root of 1981897375 is about 44518.5059834671. The cubic root of 1981897375 is about 1256.1082098661.

The spelling of 1981897375 in words is "one billion, nine hundred eighty-one million, eight hundred ninety-seven thousand, three hundred seventy-five".