18906401 has 6 divisors (see below), whose sum is σ = 19225206. Its totient is φ = 18592800.

The previous prime is 18906383. The next prime is 18906409. The reversal of 18906401 is 10460981.

It can be written as a sum of positive squares in 3 ways, for example, as 3066001 + 15840400 = 1751^2 + 3980^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18906401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18906409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1181 + ... + 6261.

It is an arithmetic number, because the mean of its divisors is an integer number (3204201).

Almost surely, 2^18906401 is an apocalyptic number.

It is an amenable number.

18906401 is a deficient number, since it is larger than the sum of its proper divisors (318805).

18906401 is an frugal number, since it uses more digits than its factorization.

18906401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5203 (or 5142 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18906401 is about 4348.1491464760. The cubic root of 18906401 is about 266.4012684170.

The spelling of 18906401 in words is "eighteen million, nine hundred six thousand, four hundred one".