221013397 has 6 divisors (see below), whose sum is σ = 242932214. Its totient is φ = 200921160.

The previous prime is 221013391. The next prime is 221013407. The reversal of 221013397 is 793310122.

221013397 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 204804721 + 16208676 = 14311^2 + 4026^2 .

It is not a de Polignac number, because 221013397 - 2²⁷ = 86795669 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 (221013391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 913158 + ... + 913399.

Almost surely, 2^221013397 is an apocalyptic number.

It is an amenable number.

221013397 is a deficient number, since it is larger than the sum of its proper divisors (21918817).

221013397 is a wasteful number, since it uses less digits than its factorization.

221013397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826579 (or 1826568 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 221013397 is about 14866.5193303611. The cubic root of 221013397 is about 604.6065761729.

The spelling of 221013397 in words is "two hundred twenty-one million, thirteen thousand, three hundred ninety-seven".