920111221 has 2 divisors, whose sum is σ = 920111222. Its totient is φ = 920111220.

The previous prime is 920111209. The next prime is 920111239. The reversal of 920111221 is 122111029.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 901500625 + 18610596 = 30025^2 + 4314^2 .

It is a cyclic number.

It is not a de Polignac number, because 920111221 - 2⁵ = 920111189 is a prime.

It is a super-2 number, since 2×920111221² = 1693209318020221682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (920111261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460055610 + 460055611.

It is an arithmetic number, because the mean of its divisors is an integer number (460055611).

Almost surely, 2^920111221 is an apocalyptic number.

It is an amenable number.

920111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

920111221 is an equidigital number, since it uses as much as digits as its factorization.

920111221 is an evil number, because the sum of its binary digits is even.

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

The square root of 920111221 is about 30333.3351446886. The cubic root of 920111221 is about 972.6280175026.

The spelling of 920111221 in words is "nine hundred twenty million, one hundred eleven thousand, two hundred twenty-one".