18732221634821 has 4 divisors (see below), whose sum is σ = 18957911052192. Its totient is φ = 18506532217452.

The previous prime is 18732221634767. The next prime is 18732221634823. The reversal of 18732221634821 is 12843612223781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18732221634821 - 2¹⁴ = 18732221618437 is a prime.

It is a super-2 number, since 2×18732221634821² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18732221634821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18732221634823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112844708561 + ... + 112844708726.

It is an arithmetic number, because the mean of its divisors is an integer number (4739477763048).

Almost surely, 2^{18732221634821} is an apocalyptic number.

It is an amenable number.

18732221634821 is a deficient number, since it is larger than the sum of its proper divisors (225689417371).

18732221634821 is an equidigital number, since it uses as much as digits as its factorization.

18732221634821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225689417370.

The product of its digits is 1548288, while the sum is 50.

The spelling of 18732221634821 in words is "eighteen trillion, seven hundred thirty-two billion, two hundred twenty-one million, six hundred thirty-four thousand, eight hundred twenty-one".