18401657 has 2 divisors, whose sum is σ = 18401658. Its totient is φ = 18401656.

The previous prime is 18401651. The next prime is 18401683. The reversal of 18401657 is 75610481.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 219961 = 4264^2 + 469^2 .

It is a cyclic number.

It is not a de Polignac number, because 18401657 - 2¹⁰ = 18400633 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18401651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200828 + 9200829.

It is an arithmetic number, because the mean of its divisors is an integer number (9200829).

Almost surely, 2^18401657 is an apocalyptic number.

It is an amenable number.

18401657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18401657 is an equidigital number, since it uses as much as digits as its factorization.

18401657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 18401657 is about 4289.7152586157. The cubic root of 18401657 is about 264.0091489407.

The spelling of 18401657 in words is "eighteen million, four hundred one thousand, six hundred fifty-seven".