18610421 has 2 divisors, whose sum is σ = 18610422. Its totient is φ = 18610420.

The previous prime is 18610399. The next prime is 18610439. The reversal of 18610421 is 12401681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 4056196 = 3815^2 + 2014^2 .

It is a cyclic number.

It is not a de Polignac number, because 18610421 - 2¹⁰ = 18609397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18610441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9305210 + 9305211.

It is an arithmetic number, because the mean of its divisors is an integer number (9305211).

Almost surely, 2^18610421 is an apocalyptic number.

It is an amenable number.

18610421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18610421 is an equidigital number, since it uses as much as digits as its factorization.

18610421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 18610421 is about 4313.9797171521. The cubic root of 18610421 is about 265.0037782777.

The spelling of 18610421 in words is "eighteen million, six hundred ten thousand, four hundred twenty-one".