815661349 has 4 divisors (see below), whose sum is σ = 815726464. Its totient is φ = 815596236.

The previous prime is 815661347. The next prime is 815661373. The reversal of 815661349 is 943166518.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 815661349 - 2¹ = 815661347 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 (815661347) by changing a digit.

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, 7167 + ... + 41020.

It is an arithmetic number, because the mean of its divisors is an integer number (203931616).

Almost surely, 2^815661349 is an apocalyptic number.

It is an amenable number.

815661349 is a deficient number, since it is larger than the sum of its proper divisors (65115).

815661349 is a wasteful number, since it uses less digits than its factorization.

815661349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65114.

The product of its digits is 155520, while the sum is 43.

The square root of 815661349 is about 28559.7855209033. The cubic root of 815661349 is about 934.3364558233.

The spelling of 815661349 in words is "eight hundred fifteen million, six hundred sixty-one thousand, three hundred forty-nine".