18621408 has 96 divisors (see below), whose sum is σ = 54020736. Its totient is φ = 5580288.

The previous prime is 18621373. The next prime is 18621431. The reversal of 18621408 is 80412681.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53491 + ... + 53837.

It is an arithmetic number, because the mean of its divisors is an integer number (562716).

Almost surely, 2^18621408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18621408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27010368).

18621408 is an abundant number, since it is smaller than the sum of its proper divisors (35399328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18621408 is a wasteful number, since it uses less digits than its factorization.

18621408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 18621408 is about 4315.2529473949. The cubic root of 18621408 is about 265.0559179495.

The spelling of 18621408 in words is "eighteen million, six hundred twenty-one thousand, four hundred eight".