221423123440 has 20 divisors (see below), whose sum is σ = 514808762184. Its totient is φ = 88569249344.

The previous prime is 221423123401. The next prime is 221423123473. The reversal of 221423123440 is 44321324122.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 221423123399 and 221423123408.

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, 1383894442 + ... + 1383894601.

Almost surely, 2^221423123440 is an apocalyptic number.

221423123440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221423123440 is an abundant number, since it is smaller than the sum of its proper divisors (293385638744).

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

221423123440 is a wasteful number, since it uses less digits than its factorization.

221423123440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767789056 (or 2767789050 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 221423123440 its reverse (44321324122), we get a palindrome (265744447562).

The spelling of 221423123440 in words is "two hundred twenty-one billion, four hundred twenty-three million, one hundred twenty-three thousand, four hundred forty".