820231681 has 8 divisors (see below), whose sum is σ = 869926464. Its totient is φ = 771706320.

The previous prime is 820231669. The next prime is 820231693. The reversal of 820231681 is 186132028.

It is an interprime number because it is at equal distance from previous prime (820231669) and next prime (820231693).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 820231681 - 2⁷ = 820231553 is a prime.

It is a super-2 number, since 2×820231681² = 1345560021032171522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820231081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 290911 + ... + 293716.

It is an arithmetic number, because the mean of its divisors is an integer number (108740808).

Almost surely, 2^820231681 is an apocalyptic number.

It is an amenable number.

820231681 is a deficient number, since it is larger than the sum of its proper divisors (49694783).

820231681 is a wasteful number, since it uses less digits than its factorization.

820231681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584711.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 820231681 is about 28639.6871665876. The cubic root of 820231681 is about 936.0783048821.

The spelling of 820231681 in words is "eight hundred twenty million, two hundred thirty-one thousand, six hundred eighty-one".