19990955 has 4 divisors (see below), whose sum is σ = 23989152. Its totient is φ = 15992760.

The previous prime is 19990937. The next prime is 19991003. The reversal of 19990955 is 55909991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55909991 = 17 ⋅3288823.

It is not a de Polignac number, because 19990955 - 2⁶ = 19990891 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1999091 + ... + 1999100.

It is an arithmetic number, because the mean of its divisors is an integer number (5997288).

Almost surely, 2^19990955 is an apocalyptic number.

19990955 is a deficient number, since it is larger than the sum of its proper divisors (3998197).

19990955 is an equidigital number, since it uses as much as digits as its factorization.

19990955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3998196.

The product of its (nonzero) digits is 164025, while the sum is 47.

The square root of 19990955 is about 4471.1245788951. The cubic root of 19990955 is about 271.4008356437.

The spelling of 19990955 in words is "nineteen million, nine hundred ninety thousand, nine hundred fifty-five".