18406837 has 4 divisors (see below), whose sum is σ = 18524236. Its totient is φ = 18289440.

The previous prime is 18406823. The next prime is 18406841. The reversal of 18406837 is 73860481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73860481 = 509 ⋅145109.

It can be written as a sum of positive squares in 2 ways, for example, as 3243601 + 15163236 = 1801^2 + 3894^2 .

It is a cyclic number.

It is not a de Polignac number, because 18406837 - 2¹⁹ = 17882549 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18406796 and 18406805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18406807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58464 + ... + 58777.

It is an arithmetic number, because the mean of its divisors is an integer number (4631059).

Almost surely, 2^18406837 is an apocalyptic number.

It is an amenable number.

18406837 is a deficient number, since it is larger than the sum of its proper divisors (117399).

18406837 is a wasteful number, since it uses less digits than its factorization.

18406837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117398.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 18406837 is about 4290.3189858098. The cubic root of 18406837 is about 264.0339191573.

The spelling of 18406837 in words is "eighteen million, four hundred six thousand, eight hundred thirty-seven".