18820988 has 6 divisors (see below), whose sum is σ = 32936736. Its totient is φ = 9410492.

The previous prime is 18820973. The next prime is 18820993. The reversal of 18820988 is 88902881.

It is a super-2 number, since 2×18820988² = 708459178592288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2352620 + ... + 2352627.

It is an arithmetic number, because the mean of its divisors is an integer number (5489456).

Almost surely, 2^18820988 is an apocalyptic number.

It is an amenable number.

18820988 is a deficient number, since it is larger than the sum of its proper divisors (14115748).

18820988 is a wasteful number, since it uses less digits than its factorization.

18820988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4705251 (or 4705249 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 44.

The square root of 18820988 is about 4338.3162632524. The cubic root of 18820988 is about 265.9994912083. Note that the first 3 decimals are identical.

The spelling of 18820988 in words is "eighteen million, eight hundred twenty thousand, nine hundred eighty-eight".