820888181 has 8 divisors (see below), whose sum is σ = 863589600. Its totient is φ = 779146480.

The previous prime is 820888171. The next prime is 820888241. The reversal of 820888181 is 181888028.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-820888181 is a prime.

It is a super-2 number, since 2×820888181² = 1347714811410977522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820888111) 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, 238175 + ... + 241596.

It is an arithmetic number, because the mean of its divisors is an integer number (107948700).

Almost surely, 2^820888181 is an apocalyptic number.

It is an amenable number.

820888181 is a deficient number, since it is larger than the sum of its proper divisors (42701419).

820888181 is a wasteful number, since it uses less digits than its factorization.

820888181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479859.

The product of its (nonzero) digits is 65536, while the sum is 44.

The square root of 820888181 is about 28651.1462423408. The cubic root of 820888181 is about 936.3279788622.

The spelling of 820888181 in words is "eight hundred twenty million, eight hundred eighty-eight thousand, one hundred eighty-one".