905901221 has 4 divisors (see below), whose sum is σ = 906143232. Its totient is φ = 905659212.

The previous prime is 905901197. The next prime is 905901223. The reversal of 905901221 is 122109509.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-905901221 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 (905901223) 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, 115301 + ... + 122906.

It is an arithmetic number, because the mean of its divisors is an integer number (226535808).

Almost surely, 2^905901221 is an apocalyptic number.

It is an amenable number.

905901221 is a deficient number, since it is larger than the sum of its proper divisors (242011).

905901221 is a wasteful number, since it uses less digits than its factorization.

905901221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242010.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 905901221 is about 30098.1929856262. The cubic root of 905901221 is about 967.5949988955.

The spelling of 905901221 in words is "nine hundred five million, nine hundred one thousand, two hundred twenty-one".