195129971645449 has 9 divisors (see below), whose sum is σ = 195299491525077. Its totient is φ = 194960598817824.

The previous prime is 195129971645443. The next prime is 195129971645459. The reversal of 195129971645449 is 944546179921591.

The square root of 195129971645449 is 13968893.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 183256767225 + 194946714878224 = 428085^2 + 13962332^2 .

It is not a de Polignac number, because 195129971645449 - 2²³ = 195129963256841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195129971645443) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 18005897659 + ... + 18005908495.

Almost surely, 2^{195129971645449} is an apocalyptic number.

195129971645449 is the 13968893-rd square number.

195129971645449 is the 6984447-th centered octagonal number.

It is an amenable number.

195129971645449 is a deficient number, since it is larger than the sum of its proper divisors (169519879628).

195129971645449 is an frugal number, since it uses more digits than its factorization.

195129971645449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24252 (or 12126 counting only the distinct ones).

The product of its digits is 881798400, while the sum is 76.

The spelling of 195129971645449 in words is "one hundred ninety-five trillion, one hundred twenty-nine billion, nine hundred seventy-one million, six hundred forty-five thousand, four hundred forty-nine".