820628971 has 2 divisors, whose sum is σ = 820628972. Its totient is φ = 820628970.

The previous prime is 820628951. The next prime is 820628987. The reversal of 820628971 is 179826028.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820628971 is a prime.

It is not a weakly prime, because it can be changed into another prime (820628911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410314485 + 410314486.

It is an arithmetic number, because the mean of its divisors is an integer number (410314486).

Almost surely, 2^820628971 is an apocalyptic number.

820628971 is a deficient number, since it is larger than the sum of its proper divisors (1).

820628971 is an equidigital number, since it uses as much as digits as its factorization.

820628971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 820628971 is about 28646.6223314373. The cubic root of 820628971 is about 936.2294144326.

The spelling of 820628971 in words is "eight hundred twenty million, six hundred twenty-eight thousand, nine hundred seventy-one".