823778957 has 2 divisors, whose sum is σ = 823778958. Its totient is φ = 823778956.

The previous prime is 823778951. The next prime is 823779031. The reversal of 823778957 is 759877328.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 808208041 + 15570916 = 28429^2 + 3946^2 .

It is a cyclic number.

It is not a de Polignac number, because 823778957 - 2⁴ = 823778941 is a prime.

It is a super-2 number, since 2×823778957² = 1357223539992015698, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (823778951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411889478 + 411889479.

It is an arithmetic number, because the mean of its divisors is an integer number (411889479).

Almost surely, 2^823778957 is an apocalyptic number.

It is an amenable number.

823778957 is a deficient number, since it is larger than the sum of its proper divisors (1).

823778957 is an equidigital number, since it uses as much as digits as its factorization.

823778957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5927040, while the sum is 56.

The square root of 823778957 is about 28701.5497316783. The cubic root of 823778957 is about 937.4257911513.

The spelling of 823778957 in words is "eight hundred twenty-three million, seven hundred seventy-eight thousand, nine hundred fifty-seven".