221020071 has 8 divisors (see below), whose sum is σ = 296340480. Its totient is φ = 146523192.

The previous prime is 221020067. The next prime is 221020091. The reversal of 221020071 is 170020122.

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

It is not a de Polignac number, because 221020071 - 2² = 221020067 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221020071.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020001) 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, 205255 + ... + 206328.

It is an arithmetic number, because the mean of its divisors is an integer number (37042560).

Almost surely, 2^221020071 is an apocalyptic number.

221020071 is a deficient number, since it is larger than the sum of its proper divisors (75320409).

221020071 is a wasteful number, since it uses less digits than its factorization.

221020071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411765.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 221020071 is about 14866.7437927745. The cubic root of 221020071 is about 604.6126619332.

Adding to 221020071 its reverse (170020122), we get a palindrome (391040193).

The spelling of 221020071 in words is "two hundred twenty-one million, twenty thousand, seventy-one".