8720444381 has 4 divisors (see below), whose sum is σ = 9513212064. Its totient is φ = 7927676700.

The previous prime is 8720444377. The next prime is 8720444413. The reversal of 8720444381 is 1834440278.

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 8720444381 - 2² = 8720444377 is a prime.

It is a super-2 number, since 2×8720444381² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8720444311) 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, 396383825 + ... + 396383846.

It is an arithmetic number, because the mean of its divisors is an integer number (2378303016).

Almost surely, 2^8720444381 is an apocalyptic number.

It is an amenable number.

8720444381 is a deficient number, since it is larger than the sum of its proper divisors (792767683).

8720444381 is a wasteful number, since it uses less digits than its factorization.

8720444381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792767682.

The product of its (nonzero) digits is 172032, while the sum is 41.

The square root of 8720444381 is about 93383.3196079471. The cubic root of 8720444381 is about 2058.3198967202.

The spelling of 8720444381 in words is "eight billion, seven hundred twenty million, four hundred forty-four thousand, three hundred eighty-one".