66722889 has 16 divisors (see below), whose sum is σ = 94970880. Its totient is φ = 41544720.

The previous prime is 66722861. The next prime is 66722891. The reversal of 66722889 is 98822766.

It is a happy number.

It is not a de Polignac number, because 66722889 - 2⁵ = 66722857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66722809) 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, 4197 + ... + 12290.

It is an arithmetic number, because the mean of its divisors is an integer number (5935680).

Almost surely, 2^66722889 is an apocalyptic number.

It is an amenable number.

66722889 is a deficient number, since it is larger than the sum of its proper divisors (28247991).

66722889 is a wasteful number, since it uses less digits than its factorization.

66722889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16580.

The product of its digits is 580608, while the sum is 48.

The square root of 66722889 is about 8168.4079844239. The cubic root of 66722889 is about 405.5940862067.

The spelling of 66722889 in words is "sixty-six million, seven hundred twenty-two thousand, eight hundred eighty-nine".