1997181925 has 12 divisors (see below), whose sum is σ = 2485652416. Its totient is φ = 1591844400.

The previous prime is 1997181899. The next prime is 1997181937. The reversal of 1997181925 is 5291817991.

It is not a de Polignac number, because 1997181925 - 2⁹ = 1997181413 is a prime.

It is a hoax number, since the sum of its digits (52) coincides with the sum of the digits of its distinct prime factors.

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 11 ways as a sum of consecutive naturals, for example, 140619 + ... + 154168.

Almost surely, 2^1997181925 is an apocalyptic number.

It is an amenable number.

1997181925 is a deficient number, since it is larger than the sum of its proper divisors (488470491).

1997181925 is a wasteful number, since it uses less digits than its factorization.

1997181925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295068 (or 295063 counting only the distinct ones).

The product of its digits is 408240, while the sum is 52.

The square root of 1997181925 is about 44689.8414071923. The cubic root of 1997181925 is about 1259.3290130716.

The spelling of 1997181925 in words is "one billion, nine hundred ninety-seven million, one hundred eighty-one thousand, nine hundred twenty-five".