18220881 has 16 divisors (see below), whose sum is σ = 28080000. Its totient is φ = 10293888.

The previous prime is 18220877. The next prime is 18220897. The reversal of 18220881 is 18802281.

It is not a de Polignac number, because 18220881 - 2² = 18220877 is a prime.

It is a super-2 number, since 2×18220881² = 664001008832322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18220841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3006 + ... + 6743.

It is an arithmetic number, because the mean of its divisors is an integer number (1755000).

Almost surely, 2^18220881 is an apocalyptic number.

It is an amenable number.

18220881 is a deficient number, since it is larger than the sum of its proper divisors (9859119).

18220881 is an equidigital number, since it uses as much as digits as its factorization.

18220881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9848.

The product of its (nonzero) digits is 2048, while the sum is 30.

The square root of 18220881 is about 4268.5923909411. The cubic root of 18220881 is about 263.1417693831.

The spelling of 18220881 in words is "eighteen million, two hundred twenty thousand, eight hundred eighty-one".