18401020 has 24 divisors (see below), whose sum is σ = 42155568. Its totient is φ = 6691200.

The previous prime is 18400981. The next prime is 18401023. The reversal of 18401020 is 2010481.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18400985 and 18401003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18401023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41601 + ... + 42040.

It is an arithmetic number, because the mean of its divisors is an integer number (1756482).

Almost surely, 2^18401020 is an apocalyptic number.

18401020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18401020 is an abundant number, since it is smaller than the sum of its proper divisors (23754548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18401020 is a wasteful number, since it uses less digits than its factorization.

18401020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83661 (or 83659 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 18401020 is about 4289.6410106208. The cubic root of 18401020 is about 264.0061025525.

The spelling of 18401020 in words is "eighteen million, four hundred one thousand, twenty".