195212621 has 4 divisors (see below), whose sum is σ = 198895932. Its totient is φ = 191529312.

The previous prime is 195212617. The next prime is 195212623. The reversal of 195212621 is 126212591.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126212591 = 89 ⋅1418119.

It can be written as a sum of positive squares in 2 ways, for example, as 149108521 + 46104100 = 12211^2 + 6790^2 .

It is a cyclic number.

It is not a de Polignac number, because 195212621 - 2² = 195212617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195212623) 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, 1841576 + ... + 1841681.

It is an arithmetic number, because the mean of its divisors is an integer number (49723983).

Almost surely, 2^195212621 is an apocalyptic number.

It is an amenable number.

195212621 is a deficient number, since it is larger than the sum of its proper divisors (3683311).

195212621 is an equidigital number, since it uses as much as digits as its factorization.

195212621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3683310.

The product of its digits is 2160, while the sum is 29.

The square root of 195212621 is about 13971.8510226813. The cubic root of 195212621 is about 580.0996865913.

The spelling of 195212621 in words is "one hundred ninety-five million, two hundred twelve thousand, six hundred twenty-one".