195661551 has 8 divisors (see below), whose sum is σ = 276228144. Its totient is φ = 122768000.

The previous prime is 195661549. The next prime is 195661559. The reversal of 195661551 is 155166591.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 195661551 - 2¹ = 195661549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195661559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1918200 + ... + 1918301.

It is an arithmetic number, because the mean of its divisors is an integer number (34528518).

Almost surely, 2^195661551 is an apocalyptic number.

195661551 is a deficient number, since it is larger than the sum of its proper divisors (80566593).

195661551 is a wasteful number, since it uses less digits than its factorization.

195661551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3836521.

The product of its digits is 40500, while the sum is 39.

The square root of 195661551 is about 13987.9073131044. The cubic root of 195661551 is about 580.5440307690.

The spelling of 195661551 in words is "one hundred ninety-five million, six hundred sixty-one thousand, five hundred fifty-one".