18234021 has 32 divisors (see below), whose sum is σ = 27320832. Its totient is φ = 10745280.

The previous prime is 18234017. The next prime is 18234023. The reversal of 18234021 is 12043281.

It is not a de Polignac number, because 18234021 - 2² = 18234017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18234023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139126 + ... + 139256.

It is an arithmetic number, because the mean of its divisors is an integer number (853776).

Almost surely, 2^18234021 is an apocalyptic number.

It is an amenable number.

18234021 is a deficient number, since it is larger than the sum of its proper divisors (9086811).

18234021 is a wasteful number, since it uses less digits than its factorization.

18234021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 18234021 is about 4270.1312626195. The cubic root of 18234021 is about 263.2050091356.

The spelling of 18234021 in words is "eighteen million, two hundred thirty-four thousand, twenty-one".