811651 has 2 divisors, whose sum is σ = 811652. Its totient is φ = 811650.

The previous prime is 811649. The next prime is 811667. The reversal of 811651 is 156118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 811651 - 2¹ = 811649 is a prime.

Together with 811649, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (811691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405825 + 405826.

It is an arithmetic number, because the mean of its divisors is an integer number (405826).

2⁸¹¹⁶⁵¹ is an apocalyptic number.

811651 is a deficient number, since it is larger than the sum of its proper divisors (1).

811651 is an equidigital number, since it uses as much as digits as its factorization.

811651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 22.

The square root of 811651 is about 900.9167553109. The cubic root of 811651 is about 93.2802660346.

Adding to 811651 its reverse (156118), we get a palindrome (967769).

The spelling of 811651 in words is "eight hundred eleven thousand, six hundred fifty-one".