221020111011021 has 24 divisors (see below), whose sum is σ = 343145110430304. Its totient is φ = 126172529794080.

The previous prime is 221020111010939. The next prime is 221020111011109. The reversal of 221020111011021 is 120110111020122.

It is a happy number.

It is not a de Polignac number, because 221020111011021 - 2²⁵ = 221020077456589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020111016021) 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, 741972595 + ... + 742270416.

It is an arithmetic number, because the mean of its divisors is an integer number (14297712934596).

Almost surely, 2^{221020111011021} is an apocalyptic number.

221020111011021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221020111011021 is a deficient number, since it is larger than the sum of its proper divisors (122124999419283).

221020111011021 is a wasteful number, since it uses less digits than its factorization.

221020111011021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1484244041 (or 1484244034 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 221020111011021 its reverse (120110111020122), we get a palindrome (341130222031143).

The spelling of 221020111011021 in words is "two hundred twenty-one trillion, twenty billion, one hundred eleven million, eleven thousand, twenty-one".