856969 has 2 divisors, whose sum is σ = 856970. Its totient is φ = 856968.

The previous prime is 856949. The next prime is 856993. The reversal of 856969 is 969658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 511225 + 345744 = 715^2 + 588^2 .

It is a cyclic number.

It is not a de Polignac number, because 856969 - 2⁷ = 856841 is a prime.

It is a super-2 number, since 2×856969² = 1468791733922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

856969 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (856909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428484 + 428485.

It is an arithmetic number, because the mean of its divisors is an integer number (428485).

2⁸⁵⁶⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

856969 is a deficient number, since it is larger than the sum of its proper divisors (1).

856969 is an equidigital number, since it uses as much as digits as its factorization.

856969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 43.

The square root of 856969 is about 925.7262014224. The cubic root of 856969 is about 94.9850022492.

The spelling of 856969 in words is "eight hundred fifty-six thousand, nine hundred sixty-nine".