195221551 has 4 divisors (see below), whose sum is σ = 223110352. Its totient is φ = 167332752.

The previous prime is 195221549. The next prime is 195221563. The reversal of 195221551 is 155122591.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 195221551 - 2¹ = 195221549 is a prime.

It is a super-2 number, since 2×195221551² = 76222907949691202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195221581) 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, 13944390 + ... + 13944403.

It is an arithmetic number, because the mean of its divisors is an integer number (55777588).

Almost surely, 2^195221551 is an apocalyptic number.

195221551 is a deficient number, since it is larger than the sum of its proper divisors (27888801).

195221551 is an equidigital number, since it uses as much as digits as its factorization.

195221551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27888800.

The product of its digits is 4500, while the sum is 31.

The square root of 195221551 is about 13972.1705901410. The cubic root of 195221551 is about 580.1085320084.

The spelling of 195221551 in words is "one hundred ninety-five million, two hundred twenty-one thousand, five hundred fifty-one".