221021007 has 16 divisors (see below), whose sum is σ = 312103680. Its totient is φ = 138834432.

The previous prime is 221020957. The next prime is 221021033. The reversal of 221021007 is 700120122.

221021007 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221021007 - 2⁷ = 221020879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19282 + ... + 28527.

It is an arithmetic number, because the mean of its divisors is an integer number (19506480).

Almost surely, 2^221021007 is an apocalyptic number.

221021007 is a deficient number, since it is larger than the sum of its proper divisors (91082673).

221021007 is a wasteful number, since it uses less digits than its factorization.

221021007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47902.

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

The square root of 221021007 is about 14866.7752723985. The cubic root of 221021007 is about 604.6135154253.

Adding to 221021007 its reverse (700120122), we get a palindrome (921141129).

The spelling of 221021007 in words is "two hundred twenty-one million, twenty-one thousand, seven".