815047949 has 4 divisors (see below), whose sum is σ = 862991964. Its totient is φ = 767103936.

The previous prime is 815047943. The next prime is 815047999. The reversal of 815047949 is 949740518.

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

It can be written as a sum of positive squares in 2 ways, for example, as 364122724 + 450925225 = 19082^2 + 21235^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815047949 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 (815047943) 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, 23971982 + ... + 23972015.

It is an arithmetic number, because the mean of its divisors is an integer number (215747991).

Almost surely, 2^815047949 is an apocalyptic number.

It is an amenable number.

815047949 is a deficient number, since it is larger than the sum of its proper divisors (47944015).

815047949 is a wasteful number, since it uses less digits than its factorization.

815047949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47944014.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 815047949 is about 28549.0446249958. The cubic root of 815047949 is about 934.1021814271.

The spelling of 815047949 in words is "eight hundred fifteen million, forty-seven thousand, nine hundred forty-nine".