18021025 has 24 divisors (see below), whose sum is σ = 25668000. Its totient is φ = 12412800.

The previous prime is 18020993. The next prime is 18021053. The reversal of 18021025 is 52012081.

It is not a de Polignac number, because 18021025 - 2⁵ = 18020993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a junction number, because it is equal to n+sod(n) for n = 18020993 and 18021011.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3501 + ... + 6949.

It is an arithmetic number, because the mean of its divisors is an integer number (1069500).

Almost surely, 2^18021025 is an apocalyptic number.

It is an amenable number.

18021025 is a deficient number, since it is larger than the sum of its proper divisors (7646975).

18021025 is a wasteful number, since it uses less digits than its factorization.

18021025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3489 (or 3484 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 18021025 is about 4245.1177839961. The cubic root of 18021025 is about 262.1761387691.

Subtracting from 18021025 its sum of digits (19), we obtain a triangular number (18021006 = T₆₀₀₃).

The spelling of 18021025 in words is "eighteen million, twenty-one thousand, twenty-five".