1997498851 has 4 divisors (see below), whose sum is σ = 1999057032. Its totient is φ = 1995940672.

The previous prime is 1997498837. The next prime is 1997498887. The reversal of 1997498851 is 1588947991.

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

It is a cyclic number.

It is not a de Polignac number, because 1997498851 - 2⁹ = 1997498339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1997498851.

It is not an unprimeable number, because it can be changed into a prime (1997498551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777166 + ... + 779731.

It is an arithmetic number, because the mean of its divisors is an integer number (499764258).

Almost surely, 2^1997498851 is an apocalyptic number.

1997498851 is a deficient number, since it is larger than the sum of its proper divisors (1558181).

1997498851 is a wasteful number, since it uses less digits than its factorization.

1997498851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1558180.

The product of its digits is 6531840, while the sum is 61.

The square root of 1997498851 is about 44693.3871059243. The cubic root of 1997498851 is about 1259.3956224262.

The spelling of 1997498851 in words is "one billion, nine hundred ninety-seven million, four hundred ninety-eight thousand, eight hundred fifty-one".