195251781 has 16 divisors (see below), whose sum is σ = 263476800. Its totient is φ = 128604288.

The previous prime is 195251747. The next prime is 195251821. The reversal of 195251781 is 187152591.

195251781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 195251781 - 2⁷ = 195251653 is a prime.

It is a super-2 number, since 2×195251781² = 76246515967343922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195251711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182115 + ... + 183183.

It is an arithmetic number, because the mean of its divisors is an integer number (16467300).

Almost surely, 2^195251781 is an apocalyptic number.

It is an amenable number.

195251781 is a deficient number, since it is larger than the sum of its proper divisors (68225019).

195251781 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (195251780) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (1748).

195251781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748.

The product of its digits is 25200, while the sum is 39.

The square root of 195251781 is about 13973.2523415274. The cubic root of 195251781 is about 580.1384736751.

The spelling of 195251781 in words is "one hundred ninety-five million, two hundred fifty-one thousand, seven hundred eighty-one".