221172713021 has 16 divisors (see below), whose sum is σ = 242975569536. Its totient is φ = 200063462976.

The previous prime is 221172713017. The next prime is 221172713039. The reversal of 221172713021 is 120317271122.

It is not a de Polignac number, because 221172713021 - 2² = 221172713017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221172713621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 372026 + ... + 762068.

It is an arithmetic number, because the mean of its divisors is an integer number (15185973096).

Almost surely, 2^221172713021 is an apocalyptic number.

It is an amenable number.

221172713021 is a deficient number, since it is larger than the sum of its proper divisors (21802856515).

221172713021 is a wasteful number, since it uses less digits than its factorization.

221172713021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390932.

The product of its (nonzero) digits is 2352, while the sum is 29.

Adding to 221172713021 its reverse (120317271122), we get a palindrome (341489984143).

The spelling of 221172713021 in words is "two hundred twenty-one billion, one hundred seventy-two million, seven hundred thirteen thousand, twenty-one".