18534421 has 2 divisors, whose sum is σ = 18534422. Its totient is φ = 18534420.

The previous prime is 18534413. The next prime is 18534431. The reversal of 18534421 is 12443581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18404100 + 130321 = 4290^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 18534421 - 2³ = 18534413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18534421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18534431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9267210 + 9267211.

It is an arithmetic number, because the mean of its divisors is an integer number (9267211).

Almost surely, 2^18534421 is an apocalyptic number.

It is an amenable number.

18534421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18534421 is an equidigital number, since it uses as much as digits as its factorization.

18534421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3840, while the sum is 28.

The square root of 18534421 is about 4305.1621339968. The cubic root of 18534421 is about 264.6425511750.

The spelling of 18534421 in words is "eighteen million, five hundred thirty-four thousand, four hundred twenty-one".