196389721 has 4 divisors (see below), whose sum is σ = 214243344. Its totient is φ = 178536100.

The previous prime is 196389707. The next prime is 196389737. The reversal of 196389721 is 127983691.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 196389721 - 2⁹ = 196389209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (196381721) 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, 8926795 + ... + 8926816.

It is an arithmetic number, because the mean of its divisors is an integer number (53560836).

Almost surely, 2^196389721 is an apocalyptic number.

196389721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

196389721 is a deficient number, since it is larger than the sum of its proper divisors (17853623).

196389721 is a wasteful number, since it uses less digits than its factorization.

196389721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17853622.

The product of its digits is 163296, while the sum is 46.

The square root of 196389721 is about 14013.9116951692. The cubic root of 196389721 is about 581.2633194466.

The spelling of 196389721 in words is "one hundred ninety-six million, three hundred eighty-nine thousand, seven hundred twenty-one".