18537421 has 8 divisors (see below), whose sum is σ = 21211904. Its totient is φ = 15869520.

The previous prime is 18537403. The next prime is 18537437. The reversal of 18537421 is 12473581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18537421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18537821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9031 + ... + 10891.

It is an arithmetic number, because the mean of its divisors is an integer number (2651488).

Almost surely, 2^18537421 is an apocalyptic number.

It is an amenable number.

18537421 is a deficient number, since it is larger than the sum of its proper divisors (2674483).

18537421 is a wasteful number, since it uses less digits than its factorization.

18537421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3291.

The product of its digits is 6720, while the sum is 31.

The square root of 18537421 is about 4305.5105388328. The cubic root of 18537421 is about 264.6568288411.

The spelling of 18537421 in words is "eighteen million, five hundred thirty-seven thousand, four hundred twenty-one".