220721031939 has 4 divisors (see below), whose sum is σ = 294294709256. Its totient is φ = 147147354624.

The previous prime is 220721031913. The next prime is 220721031977. The reversal of 220721031939 is 939130127022.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 220721031939 - 2¹² = 220721027843 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220721031897 and 220721031906.

It is not an unprimeable number, because it can be changed into a prime (220722031939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36786838654 + ... + 36786838659.

It is an arithmetic number, because the mean of its divisors is an integer number (73573677314).

Almost surely, 2^220721031939 is an apocalyptic number.

220721031939 is a deficient number, since it is larger than the sum of its proper divisors (73573677317).

220721031939 is an equidigital number, since it uses as much as digits as its factorization.

220721031939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73573677316.

The product of its (nonzero) digits is 40824, while the sum is 39.

The spelling of 220721031939 in words is "two hundred twenty billion, seven hundred twenty-one million, thirty-one thousand, nine hundred thirty-nine".