19901995 has 4 divisors (see below), whose sum is σ = 23882400. Its totient is φ = 15921592.

The previous prime is 19901963. The next prime is 19902011. The reversal of 19901995 is 59910991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59910991 = 7 ⋅8558713.

It is a cyclic number.

It is not a de Polignac number, because 19901995 - 2⁵ = 19901963 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1990195 + ... + 1990204.

It is an arithmetic number, because the mean of its divisors is an integer number (5970600).

Almost surely, 2^19901995 is an apocalyptic number.

19901995 is a deficient number, since it is larger than the sum of its proper divisors (3980405).

19901995 is an equidigital number, since it uses as much as digits as its factorization.

19901995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3980404.

The product of its (nonzero) digits is 32805, while the sum is 43.

The square root of 19901995 is about 4461.1652065352. The cubic root of 19901995 is about 270.9976579637.

The spelling of 19901995 in words is "nineteen million, nine hundred one thousand, nine hundred ninety-five".