819997949 has 4 divisors (see below), whose sum is σ = 820108320. Its totient is φ = 819887580.

The previous prime is 819997931. The next prime is 819997963. The reversal of 819997949 is 949799918.

819997949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 819997949 - 2⁸ = 819997693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819997999) 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, 43169 + ... + 59190.

It is an arithmetic number, because the mean of its divisors is an integer number (205027080).

Almost surely, 2^819997949 is an apocalyptic number.

It is an amenable number.

819997949 is a deficient number, since it is larger than the sum of its proper divisors (110371).

819997949 is a wasteful number, since it uses less digits than its factorization.

819997949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110370.

The product of its digits is 13226976, while the sum is 65.

The square root of 819997949 is about 28635.6063145169. The cubic root of 819997949 is about 935.9893819412.

It can be divided in two parts, 8199979 and 49, that added together give a palindrome (8200028).

The spelling of 819997949 in words is "eight hundred nineteen million, nine hundred ninety-seven thousand, nine hundred forty-nine".