196712220821 has 4 divisors (see below), whose sum is σ = 196715179200. Its totient is φ = 196709262444.

The previous prime is 196712220791. The next prime is 196712220823. The reversal of 196712220821 is 128022217691.

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, and also an emirpimes, since its reverse is a distinct semiprime: 128022217691 = 78283 ⋅1635377.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-196712220821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (196712220823) 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, 1377101 + ... + 1513218.

It is an arithmetic number, because the mean of its divisors is an integer number (49178794800).

Almost surely, 2^196712220821 is an apocalyptic number.

It is an amenable number.

196712220821 is a deficient number, since it is larger than the sum of its proper divisors (2958379).

196712220821 is an equidigital number, since it uses as much as digits as its factorization.

196712220821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2958378.

The product of its (nonzero) digits is 48384, while the sum is 41.

The spelling of 196712220821 in words is "one hundred ninety-six billion, seven hundred twelve million, two hundred twenty thousand, eight hundred twenty-one".