221868457 has 4 divisors (see below), whose sum is σ = 229025536. Its totient is φ = 214711380.

The previous prime is 221868443. The next prime is 221868467. The reversal of 221868457 is 754868122.

It is a happy number.

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 not a de Polignac number, because 221868457 - 2¹⁵ = 221835689 is a prime.

It is a super-2 number, since 2×221868457² = 98451224423121698, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221868467) 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, 3578493 + ... + 3578554.

It is an arithmetic number, because the mean of its divisors is an integer number (57256384).

Almost surely, 2^221868457 is an apocalyptic number.

It is an amenable number.

221868457 is a deficient number, since it is larger than the sum of its proper divisors (7157079).

221868457 is an equidigital number, since it uses as much as digits as its factorization.

221868457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7157078.

The product of its digits is 215040, while the sum is 43.

The square root of 221868457 is about 14895.2494776019. The cubic root of 221868457 is about 605.3852765320.

The spelling of 221868457 in words is "two hundred twenty-one million, eight hundred sixty-eight thousand, four hundred fifty-seven".