221020989 has 32 divisors (see below), whose sum is σ = 347043840. Its totient is φ = 122496192.

The previous prime is 221020957. The next prime is 221021033. The reversal of 221020989 is 989020122.

It is a happy number.

221020989 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 221020989 - 2⁵ = 221020957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020489) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 140992 + ... + 142550.

It is an arithmetic number, because the mean of its divisors is an integer number (10845120).

Almost surely, 2^221020989 is an apocalyptic number.

It is an amenable number.

221020989 is a deficient number, since it is larger than the sum of its proper divisors (126022851).

221020989 is a wasteful number, since it uses less digits than its factorization.

221020989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1769.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 221020989 is about 14866.7746670218. The cubic root of 221020989 is about 604.6134990120.

The spelling of 221020989 in words is "two hundred twenty-one million, twenty thousand, nine hundred eighty-nine".