1981172195 has 8 divisors (see below), whose sum is σ = 2377801536. Its totient is φ = 1584674496.

The previous prime is 1981172173. The next prime is 1981172251. The reversal of 1981172195 is 5912711891.

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 1981172195 - 2⁶ = 1981172131 is a prime.

It is a super-2 number, since 2×1981172195² = 7850086532482236050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3959 + ... + 63071.

It is an arithmetic number, because the mean of its divisors is an integer number (297225192).

Almost surely, 2^1981172195 is an apocalyptic number.

1981172195 is a deficient number, since it is larger than the sum of its proper divisors (396629341).

1981172195 is an equidigital number, since it uses as much as digits as its factorization.

1981172195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65821.

The product of its digits is 45360, while the sum is 44.

The square root of 1981172195 is about 44510.3605354978. The cubic root of 1981172195 is about 1255.9549870527.

The spelling of 1981172195 in words is "one billion, nine hundred eighty-one million, one hundred seventy-two thousand, one hundred ninety-five".