18191020 has 24 divisors (see below), whose sum is σ = 40449024. Its totient is φ = 6848256.

The previous prime is 18190979. The next prime is 18191023. The reversal of 18191020 is 2019181.

It is a junction number, because it is equal to n+sod(n) for n = 18190982 and 18191000.

It is not an unprimeable number, because it can be changed into a prime (18191023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26412 + ... + 27091.

It is an arithmetic number, because the mean of its divisors is an integer number (1685376).

Almost surely, 2^18191020 is an apocalyptic number.

18191020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18191020 is an abundant number, since it is smaller than the sum of its proper divisors (22258004).

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

18191020 is a wasteful number, since it uses less digits than its factorization.

18191020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53529 (or 53527 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 18191020 is about 4265.0931994506. The cubic root of 18191020 is about 262.9979422220.

The spelling of 18191020 in words is "eighteen million, one hundred ninety-one thousand, twenty".