1995208139 has 4 divisors (see below), whose sum is σ = 2037659424. Its totient is φ = 1952756856.

The previous prime is 1995208129. The next prime is 1995208147. The reversal of 1995208139 is 9318025991.

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 1995208139 - 2⁸ = 1995207883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 42451237 = 1995208139 / (1 + 9 + 9 + 5 + 2 + 0 + 8 + 1 + 3 + 9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1995208093 and 1995208102.

It is not an unprimeable number, because it can be changed into a prime (1995208109) 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, 21225572 + ... + 21225665.

It is an arithmetic number, because the mean of its divisors is an integer number (509414856).

Almost surely, 2^1995208139 is an apocalyptic number.

1995208139 is a deficient number, since it is larger than the sum of its proper divisors (42451285).

1995208139 is an equidigital number, since it uses as much as digits as its factorization.

1995208139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42451284.

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 1995208139 is about 44667.7527865461. The cubic root of 1995208139 is about 1258.9140174492.

The spelling of 1995208139 in words is "one billion, nine hundred ninety-five million, two hundred eight thousand, one hundred thirty-nine".