18437421 has 16 divisors (see below), whose sum is σ = 25804800. Its totient is φ = 11687280.

The previous prime is 18437407. The next prime is 18437423. The reversal of 18437421 is 12473481.

It is not a de Polignac number, because 18437421 - 2⁵ = 18437389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18437423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12480 + ... + 13878.

It is an arithmetic number, because the mean of its divisors is an integer number (1612800).

Almost surely, 2^18437421 is an apocalyptic number.

It is an amenable number.

18437421 is a deficient number, since it is larger than the sum of its proper divisors (7367379).

18437421 is a wasteful number, since it uses less digits than its factorization.

18437421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1616.

The product of its digits is 5376, while the sum is 30.

The square root of 18437421 is about 4293.8818102039. The cubic root of 18437421 is about 264.1800739988.

The spelling of 18437421 in words is "eighteen million, four hundred thirty-seven thousand, four hundred twenty-one".