221202121021 has 32 divisors (see below), whose sum is σ = 263186085888. Its totient is φ = 181924427520.

The previous prime is 221202120961. The next prime is 221202121031. The reversal of 221202121021 is 120121202122.

It is a happy number.

It is not a de Polignac number, because 221202121021 - 2¹⁵ = 221202088253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221202120986 and 221202121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221202121031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13994895 + ... + 14010691.

It is an arithmetic number, because the mean of its divisors is an integer number (8224565184).

Almost surely, 2^221202121021 is an apocalyptic number.

It is an amenable number.

221202121021 is a deficient number, since it is larger than the sum of its proper divisors (41983964867).

221202121021 is a wasteful number, since it uses less digits than its factorization.

221202121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16381.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221202121021 its reverse (120121202122), we get a palindrome (341323323143).

The spelling of 221202121021 in words is "two hundred twenty-one billion, two hundred two million, one hundred twenty-one thousand, twenty-one".