221220107026731 has 24 divisors (see below), whose sum is σ = 321089754454560. Its totient is φ = 146765490393600.

The previous prime is 221220107026697. The next prime is 221220107026733. The reversal of 221220107026731 is 137620701022122.

It is not a de Polignac number, because 221220107026731 - 2⁷ = 221220107026603 is a prime.

It is a super-2 number, since 2×221220107026731² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221220107026733) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21500655 + ... + 30078536.

It is an arithmetic number, because the mean of its divisors is an integer number (13378739768940).

Almost surely, 2^{221220107026731} is an apocalyptic number.

221220107026731 is a deficient number, since it is larger than the sum of its proper divisors (99869647427829).

221220107026731 is a wasteful number, since it uses less digits than its factorization.

221220107026731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51581507 (or 51581504 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

Adding to 221220107026731 its reverse (137620701022122), we get a palindrome (358840808048853).

The spelling of 221220107026731 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred seven million, twenty-six thousand, seven hundred thirty-one".