911000021221 has 4 divisors (see below), whose sum is σ = 911002359852. Its totient is φ = 910997682592.

The previous prime is 911000021219. The next prime is 911000021249. The reversal of 911000021221 is 122120000119.

It is a happy number.

911000021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 774595372321 + 136404648900 = 880111^2 + 369330^2 .

It is a cyclic number.

It is not a de Polignac number, because 911000021221 - 2¹ = 911000021219 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 (911000028221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 428590 + ... + 1416223.

It is an arithmetic number, because the mean of its divisors is an integer number (227750589963).

Almost surely, 2^911000021221 is an apocalyptic number.

It is an amenable number.

911000021221 is a deficient number, since it is larger than the sum of its proper divisors (2338631).

911000021221 is a wasteful number, since it uses less digits than its factorization.

911000021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338630.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 911000021221 in words is "nine hundred eleven billion, twenty-one thousand, two hundred twenty-one".