911231400221 has 4 divisors (see below), whose sum is σ = 912134504700. Its totient is φ = 910328295744.

The previous prime is 911231400217. The next prime is 911231400229. The reversal of 911231400221 is 122004132119.

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 191467504900 + 719763895321 = 437570^2 + 848389^2 .

It is a cyclic number.

It is not a de Polignac number, because 911231400221 - 2² = 911231400217 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 (911231400229) 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, 451550726 + ... + 451552743.

It is an arithmetic number, because the mean of its divisors is an integer number (228033626175).

Almost surely, 2^911231400221 is an apocalyptic number.

It is an amenable number.

911231400221 is a deficient number, since it is larger than the sum of its proper divisors (903104479).

911231400221 is a wasteful number, since it uses less digits than its factorization.

911231400221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903104478.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 911231400221 in words is "nine hundred eleven billion, two hundred thirty-one million, four hundred thousand, two hundred twenty-one".