195821051 has 2 divisors, whose sum is σ = 195821052. Its totient is φ = 195821050.

The previous prime is 195821033. The next prime is 195821089. The reversal of 195821051 is 150128591.

It is a weak prime.

It is an emirp because it is prime and its reverse (150128591) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-195821051 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 195820999 and 195821017.

It is not a weakly prime, because it can be changed into another prime (195821851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97910525 + 97910526.

It is an arithmetic number, because the mean of its divisors is an integer number (97910526).

Almost surely, 2^195821051 is an apocalyptic number.

195821051 is a deficient number, since it is larger than the sum of its proper divisors (1).

195821051 is an equidigital number, since it uses as much as digits as its factorization.

195821051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 32.

The square root of 195821051 is about 13993.6075048574. The cubic root of 195821051 is about 580.7017378278.

The spelling of 195821051 in words is "one hundred ninety-five million, eight hundred twenty-one thousand, fifty-one".