66610026 has 80 divisors (see below), whose sum is σ = 172149120. Its totient is φ = 18856800.

The previous prime is 66610021. The next prime is 66610043. The reversal of 66610026 is 62001666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66610021) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 171040 + ... + 171428.

It is an arithmetic number, because the mean of its divisors is an integer number (2151864).

Almost surely, 2^66610026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66610026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86074560).

66610026 is an abundant number, since it is smaller than the sum of its proper divisors (105539094).

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

66610026 is a wasteful number, since it uses less digits than its factorization.

66610026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 66610026 is about 8161.4965539416. The cubic root of 66610026 is about 405.3652671764.

The spelling of 66610026 in words is "sixty-six million, six hundred ten thousand, twenty-six".