1995197681 has 4 divisors (see below), whose sum is σ = 2005224000. Its totient is φ = 1985171364.

The previous prime is 1995197671. The next prime is 1995197717. The reversal of 1995197681 is 1867915991.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1867915991 = 6733 ⋅277427.

It is a cyclic number.

It is not a de Polignac number, because 1995197681 - 2¹⁰ = 1995196657 is a prime.

It is a super-2 number, since 2×1995197681² = 7961627572535555522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1995197671) 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, 5012861 + ... + 5013258.

It is an arithmetic number, because the mean of its divisors is an integer number (501306000).

Almost surely, 2^1995197681 is an apocalyptic number.

It is an amenable number.

1995197681 is a deficient number, since it is larger than the sum of its proper divisors (10026319).

1995197681 is a wasteful number, since it uses less digits than its factorization.

1995197681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10026318.

The product of its digits is 1224720, while the sum is 56.

The square root of 1995197681 is about 44667.6357220751. The cubic root of 1995197681 is about 1258.9118178883.

The spelling of 1995197681 in words is "one billion, nine hundred ninety-five million, one hundred ninety-seven thousand, six hundred eighty-one".