81798307 has 4 divisors (see below), whose sum is σ = 81886176. Its totient is φ = 81710440.

The previous prime is 81798293. The next prime is 81798313. The reversal of 81798307 is 70389718.

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

It is a cyclic number.

It is not a de Polignac number, because 81798307 - 2¹⁵ = 81765539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81798317) 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, 42523 + ... + 44404.

It is an arithmetic number, because the mean of its divisors is an integer number (20471544).

Almost surely, 2^81798307 is an apocalyptic number.

81798307 is a deficient number, since it is larger than the sum of its proper divisors (87869).

81798307 is an equidigital number, since it uses as much as digits as its factorization.

81798307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87868.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 81798307 is about 9044.2416486956. The cubic root of 81798307 is about 434.0916563339.

The spelling of 81798307 in words is "eighty-one million, seven hundred ninety-eight thousand, three hundred seven".