19947155 has 4 divisors (see below), whose sum is σ = 23936592. Its totient is φ = 15957720.

The previous prime is 19947143. The next prime is 19947203. The reversal of 19947155 is 55174991.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 19947155 - 2⁴ = 19947139 is a prime.

It is a Duffinian number.

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, 1994711 + ... + 1994720.

It is an arithmetic number, because the mean of its divisors is an integer number (5984148).

Almost surely, 2^19947155 is an apocalyptic number.

19947155 is a deficient number, since it is larger than the sum of its proper divisors (3989437).

19947155 is an equidigital number, since it uses as much as digits as its factorization.

19947155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3989436.

The product of its digits is 56700, while the sum is 41.

The square root of 19947155 is about 4466.2237964527. The cubic root of 19947155 is about 271.2024784553.

It can be divided in two parts, 19947 and 155, that added together give a palindrome (20102).

The spelling of 19947155 in words is "nineteen million, nine hundred forty-seven thousand, one hundred fifty-five".