81634293 has 12 divisors (see below), whose sum is σ = 126986860. Its totient is φ = 50236416.

The previous prime is 81634277. The next prime is 81634297. The reversal of 81634293 is 39243618.

It can be written as a sum of positive squares in 2 ways, for example, as 13373649 + 68260644 = 3657^2 + 8262^2 .

It is not a de Polignac number, because 81634293 - 2⁴ = 81634277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81634297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 348748 + ... + 348981.

Almost surely, 2^81634293 is an apocalyptic number.

It is an amenable number.

81634293 is a deficient number, since it is larger than the sum of its proper divisors (45352567).

81634293 is a wasteful number, since it uses less digits than its factorization.

81634293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697748 (or 697745 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 81634293 is about 9035.1697825774. The cubic root of 81634293 is about 433.8013294292.

The spelling of 81634293 in words is "eighty-one million, six hundred thirty-four thousand, two hundred ninety-three".