221278013 has 8 divisors (see below), whose sum is σ = 242035680. Its totient is φ = 200627280.

The previous prime is 221278007. The next prime is 221278037. The reversal of 221278013 is 310872122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221278013 - 2⁴ = 221277997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221278073) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22370 + ... + 30707.

It is an arithmetic number, because the mean of its divisors is an integer number (30254460).

Almost surely, 2^221278013 is an apocalyptic number.

It is an amenable number.

221278013 is a deficient number, since it is larger than the sum of its proper divisors (20757667).

221278013 is a wasteful number, since it uses less digits than its factorization.

221278013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53467.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 221278013 is about 14875.4163975332. The cubic root of 221278013 is about 604.8477753758.

The spelling of 221278013 in words is "two hundred twenty-one million, two hundred seventy-eight thousand, thirteen".