1997842521 has 8 divisors (see below), whose sum is σ = 2664255424. Its totient is φ = 1331662320.

The previous prime is 1997842481. The next prime is 1997842531. The reversal of 1997842521 is 1252487991.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1997842521 - 2¹¹ = 1997840473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1997842531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37045 + ... + 73266.

It is an arithmetic number, because the mean of its divisors is an integer number (333031928).

Almost surely, 2^1997842521 is an apocalyptic number.

It is an amenable number.

1997842521 is a deficient number, since it is larger than the sum of its proper divisors (666412903).

1997842521 is a wasteful number, since it uses less digits than its factorization.

1997842521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116351.

The product of its digits is 362880, while the sum is 48.

The square root of 1997842521 is about 44697.2316928017. The cubic root of 1997842521 is about 1259.4678446912.

The spelling of 1997842521 in words is "one billion, nine hundred ninety-seven million, eight hundred forty-two thousand, five hundred twenty-one".