823785251 has 4 divisors (see below), whose sum is σ = 824747352. Its totient is φ = 822823152.

The previous prime is 823785229. The next prime is 823785283. The reversal of 823785251 is 152587328.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-823785251 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 823785199 and 823785208.

It is not an unprimeable number, because it can be changed into a prime (823781251) 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, 479765 + ... + 481478.

It is an arithmetic number, because the mean of its divisors is an integer number (206186838).

Almost surely, 2^823785251 is an apocalyptic number.

823785251 is a deficient number, since it is larger than the sum of its proper divisors (962101).

823785251 is an equidigital number, since it uses as much as digits as its factorization.

823785251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 962100.

The product of its digits is 134400, while the sum is 41.

The square root of 823785251 is about 28701.6593771162. The cubic root of 823785251 is about 937.4281785809.

The spelling of 823785251 in words is "eight hundred twenty-three million, seven hundred eighty-five thousand, two hundred fifty-one".