19949155 has 4 divisors (see below), whose sum is σ = 23938992. Its totient is φ = 15959320.

The previous prime is 19949093. The next prime is 19949173. The reversal of 19949155 is 55194991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55194991 = 2477 ⋅22283.

It is not a de Polignac number, because 19949155 - 2¹⁵ = 19916387 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, 1994911 + ... + 1994920.

It is an arithmetic number, because the mean of its divisors is an integer number (5984748).

Almost surely, 2^19949155 is an apocalyptic number.

19949155 is a deficient number, since it is larger than the sum of its proper divisors (3989837).

19949155 is an equidigital number, since it uses as much as digits as its factorization.

19949155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3989836.

The product of its digits is 72900, while the sum is 43.

The square root of 19949155 is about 4466.4476936375. The cubic root of 19949155 is about 271.2115421845.

The spelling of 19949155 in words is "nineteen million, nine hundred forty-nine thousand, one hundred fifty-five".