21818709814972 has 12 divisors (see below), whose sum is σ = 43637419630000. Its totient is φ = 9350875634976.

The previous prime is 21818709814919. The next prime is 21818709814981. The reversal of 21818709814972 is 27941890781812.

21818709814972 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21818709814898 and 21818709814907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389619818097 + ... + 389619818152.

Almost surely, 2^{21818709814972} is an apocalyptic number.

It is an amenable number.

21818709814972 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21818709814972 is a wasteful number, since it uses less digits than its factorization.

21818709814972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779239636260 (or 779239636258 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 67.

The spelling of 21818709814972 in words is "twenty-one trillion, eight hundred eighteen billion, seven hundred nine million, eight hundred fourteen thousand, nine hundred seventy-two".