1983721197 has 4 divisors (see below), whose sum is σ = 2644961600. Its totient is φ = 1322480796.

The previous prime is 1983721169. The next prime is 1983721213. The reversal of 1983721197 is 7911273891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1983721197 - 2¹⁰ = 1983720173 is a prime.

It is a super-2 number, since 2×1983721197² = 7870299574854225618, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1983721147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330620197 + ... + 330620202.

It is an arithmetic number, because the mean of its divisors is an integer number (661240400).

Almost surely, 2^1983721197 is an apocalyptic number.

It is an amenable number.

1983721197 is a deficient number, since it is larger than the sum of its proper divisors (661240403).

1983721197 is an equidigital number, since it uses as much as digits as its factorization.

1983721197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661240402.

The product of its digits is 190512, while the sum is 48.

The square root of 1983721197 is about 44538.9851366194. The cubic root of 1983721197 is about 1256.4933989015.

The spelling of 1983721197 in words is "one billion, nine hundred eighty-three million, seven hundred twenty-one thousand, one hundred ninety-seven".