66722944 has 32 divisors (see below), whose sum is σ = 134441100. Its totient is φ = 32980992.

The previous prime is 66722941. The next prime is 66722947. The reversal of 66722944 is 44922766.

It is an interprime number because it is at equal distance from previous prime (66722941) and next prime (66722947).

It can be written as a sum of positive squares in 2 ways, for example, as 65934400 + 788544 = 8120^2 + 888^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 66722897 and 66722906.

It is not an unprimeable number, because it can be changed into a prime (66722941) 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, 8464 + ... + 14320.

Almost surely, 2^66722944 is an apocalyptic number.

66722944 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66722944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67220550).

66722944 is an abundant number, since it is smaller than the sum of its proper divisors (67718156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66722944 is an equidigital number, since it uses as much as digits as its factorization.

66722944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5960 (or 5948 counting only the distinct ones).

The product of its digits is 145152, while the sum is 40.

The square root of 66722944 is about 8168.4113510523. The cubic root of 66722944 is about 405.5941976510.

The spelling of 66722944 in words is "sixty-six million, seven hundred twenty-two thousand, nine hundred forty-four".