195720621 has 4 divisors (see below), whose sum is σ = 260960832. Its totient is φ = 130480412.

The previous prime is 195720619. The next prime is 195720661. The reversal of 195720621 is 126027591.

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 195720621 - 2¹ = 195720619 is a prime.

It is a super-2 number, since 2×195720621² = 76613122969251282, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195720611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32620101 + ... + 32620106.

It is an arithmetic number, because the mean of its divisors is an integer number (65240208).

Almost surely, 2^195720621 is an apocalyptic number.

It is an amenable number.

195720621 is a deficient number, since it is larger than the sum of its proper divisors (65240211).

195720621 is an equidigital number, since it uses as much as digits as its factorization.

195720621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65240210.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 195720621 is about 13990.0186204308. The cubic root of 195720621 is about 580.6024467520.

It can be divided in two parts, 1957 and 20621, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 195720621 in words is "one hundred ninety-five million, seven hundred twenty thousand, six hundred twenty-one".