20111021221 has 8 divisors (see below), whose sum is σ = 21124393344. Its totient is φ = 19109230800.

The previous prime is 20111021197. The next prime is 20111021237. The reversal of 20111021221 is 12212011102.

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-20111021221 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 (20111021321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2891866 + ... + 2898811.

It is an arithmetic number, because the mean of its divisors is an integer number (2640549168).

Almost surely, 2^20111021221 is an apocalyptic number.

It is an amenable number.

20111021221 is a deficient number, since it is larger than the sum of its proper divisors (1013372123).

20111021221 is a wasteful number, since it uses less digits than its factorization.

20111021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5790851.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20111021221 its reverse (12212011102), we get a palindrome (32323032323).

It can be divided in two parts, 2011102 and 1221, that multiplied together give a palindrome (2455555542).

The spelling of 20111021221 in words is "twenty billion, one hundred eleven million, twenty-one thousand, two hundred twenty-one".