195867782021 has 4 divisors (see below), whose sum is σ = 202621843500. Its totient is φ = 189113720544.

The previous prime is 195867781987. The next prime is 195867782041. The reversal of 195867782021 is 120287768591.

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

It can be written as a sum of positive squares in 2 ways, for example, as 149378385025 + 46489396996 = 386495^2 + 215614^2 .

It is a cyclic number.

It is not a de Polignac number, because 195867782021 - 2¹⁴ = 195867765637 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 (195867782041) 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, 3377030696 + ... + 3377030753.

It is an arithmetic number, because the mean of its divisors is an integer number (50655460875).

Almost surely, 2^195867782021 is an apocalyptic number.

It is an amenable number.

195867782021 is a deficient number, since it is larger than the sum of its proper divisors (6754061479).

195867782021 is an equidigital number, since it uses as much as digits as its factorization.

195867782021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6754061478.

The product of its (nonzero) digits is 3386880, while the sum is 56.

The spelling of 195867782021 in words is "one hundred ninety-five billion, eight hundred sixty-seven million, seven hundred eighty-two thousand, twenty-one".