815642633 has 4 divisors (see below), whose sum is σ = 878384388. Its totient is φ = 752900880.

The previous prime is 815642573. The next prime is 815642647. The reversal of 815642633 is 336246518.

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 490489609 + 325153024 = 22147^2 + 18032^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815642633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (815642033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31370858 + ... + 31370883.

It is an arithmetic number, because the mean of its divisors is an integer number (219596097).

Almost surely, 2^815642633 is an apocalyptic number.

It is an amenable number.

815642633 is a deficient number, since it is larger than the sum of its proper divisors (62741755).

815642633 is a wasteful number, since it uses less digits than its factorization.

815642633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62741754.

The product of its digits is 103680, while the sum is 38.

The square root of 815642633 is about 28559.4578554986. The cubic root of 815642633 is about 934.3293094036.

The spelling of 815642633 in words is "eight hundred fifteen million, six hundred forty-two thousand, six hundred thirty-three".