221912639 has 8 divisors (see below), whose sum is σ = 239388912. Its totient is φ = 204494400.

The previous prime is 221912617. The next prime is 221912651. The reversal of 221912639 is 936219122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221912639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221912599 and 221912608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221912839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6389 + ... + 22014.

It is an arithmetic number, because the mean of its divisors is an integer number (29923614).

Almost surely, 2^221912639 is an apocalyptic number.

221912639 is a deficient number, since it is larger than the sum of its proper divisors (17476273).

221912639 is a wasteful number, since it uses less digits than its factorization.

221912639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29017.

The product of its digits is 11664, while the sum is 35.

The square root of 221912639 is about 14896.7324940740. The cubic root of 221912639 is about 605.4254585350.

The spelling of 221912639 in words is "two hundred twenty-one million, nine hundred twelve thousand, six hundred thirty-nine".