819992649 has 16 divisors (see below), whose sum is σ = 1250854272. Its totient is φ = 468064128.

The previous prime is 819992629. The next prime is 819992669. The reversal of 819992649 is 946299918.

It is an interprime number because it is at equal distance from previous prime (819992629) and next prime (819992669).

It is not a de Polignac number, because 819992649 - 2⁵ = 819992617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (819992609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 474 + ... + 40499.

It is an arithmetic number, because the mean of its divisors is an integer number (78178392).

Almost surely, 2^819992649 is an apocalyptic number.

It is an amenable number.

819992649 is a deficient number, since it is larger than the sum of its proper divisors (430861623).

819992649 is a wasteful number, since it uses less digits than its factorization.

819992649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41936.

The product of its digits is 2519424, while the sum is 57.

The square root of 819992649 is about 28635.5137722374. The cubic root of 819992649 is about 935.9873653693.

It can be divided in two parts, 81999 and 2649, that added together give a palindrome (84648).

The spelling of 819992649 in words is "eight hundred nineteen million, nine hundred ninety-two thousand, six hundred forty-nine".