913428221 has 4 divisors (see below), whose sum is σ = 932862912. Its totient is φ = 893993532.

The previous prime is 913428203. The next prime is 913428223. The reversal of 913428221 is 122824319.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122824319 = 233 ⋅527143.

It is a cyclic number.

It is not a de Polignac number, because 913428221 - 2¹⁰ = 913427197 is a prime.

It is a super-2 number, since 2×913428221² = 1668702229838449682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (913428223) 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, 9717275 + ... + 9717368.

It is an arithmetic number, because the mean of its divisors is an integer number (233215728).

Almost surely, 2^913428221 is an apocalyptic number.

It is an amenable number.

913428221 is a deficient number, since it is larger than the sum of its proper divisors (19434691).

913428221 is a wasteful number, since it uses less digits than its factorization.

913428221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19434690.

The product of its digits is 6912, while the sum is 32.

The square root of 913428221 is about 30222.9750521023. The cubic root of 913428221 is about 970.2674789333.

The spelling of 913428221 in words is "nine hundred thirteen million, four hundred twenty-eight thousand, two hundred twenty-one".