816868651 has 2 divisors, whose sum is σ = 816868652. Its totient is φ = 816868650.

The previous prime is 816868583. The next prime is 816868669. The reversal of 816868651 is 156868618.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816868651 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 816868595 and 816868604.

It is not a weakly prime, because it can be changed into another prime (816868951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408434325 + 408434326.

It is an arithmetic number, because the mean of its divisors is an integer number (408434326).

Almost surely, 2^816868651 is an apocalyptic number.

816868651 is a deficient number, since it is larger than the sum of its proper divisors (1).

816868651 is an equidigital number, since it uses as much as digits as its factorization.

816868651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 552960, while the sum is 49.

The square root of 816868651 is about 28580.9141036462. The cubic root of 816868651 is about 934.7972149282.

The spelling of 816868651 in words is "eight hundred sixteen million, eight hundred sixty-eight thousand, six hundred fifty-one".