18626821 has 8 divisors (see below), whose sum is σ = 19660320. Its totient is φ = 17598672.

The previous prime is 18626809. The next prime is 18626837. The reversal of 18626821 is 12862681.

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

It is a cyclic number.

It is not a de Polignac number, because 18626821 - 2²³ = 10238213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18620821) 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, 7311 + ... + 9523.

It is an arithmetic number, because the mean of its divisors is an integer number (2457540).

Almost surely, 2^18626821 is an apocalyptic number.

It is an amenable number.

18626821 is a deficient number, since it is larger than the sum of its proper divisors (1033499).

18626821 is a wasteful number, since it uses less digits than its factorization.

18626821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2675.

The product of its digits is 9216, while the sum is 34.

The square root of 18626821 is about 4315.8800956468. The cubic root of 18626821 is about 265.0815982254.

The spelling of 18626821 in words is "eighteen million, six hundred twenty-six thousand, eight hundred twenty-one".