18631021 has 8 divisors (see below), whose sum is σ = 19393920. Its totient is φ = 17876208.

The previous prime is 18631009. The next prime is 18631049. The reversal of 18631021 is 12013681.

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 18631021 - 2⁹ = 18630509 is a prime.

It is a super-2 number, since 2×18631021² = 694229887004882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18630983 and 18631001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18631051) 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, 2920 + ... + 6766.

It is an arithmetic number, because the mean of its divisors is an integer number (2424240).

Almost surely, 2^18631021 is an apocalyptic number.

It is an amenable number.

18631021 is a deficient number, since it is larger than the sum of its proper divisors (762899).

18631021 is a wasteful number, since it uses less digits than its factorization.

18631021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4043.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 18631021 is about 4316.3666433703. The cubic root of 18631021 is about 265.1015203768.

The spelling of 18631021 in words is "eighteen million, six hundred thirty-one thousand, twenty-one".