66761172 has 60 divisors (see below), whose sum is σ = 179276020. Its totient is φ = 21648384.

The previous prime is 66761171. The next prime is 66761173. The reversal of 66761172 is 27116766.

It is an interprime number because it is at equal distance from previous prime (66761171) and next prime (66761173).

It can be written as a sum of positive squares in 2 ways, for example, as 37015056 + 29746116 = 6084^2 + 5454^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66761171) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9204 + ... + 14772.

Almost surely, 2^66761172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66761172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89638010).

66761172 is an abundant number, since it is smaller than the sum of its proper divisors (112514848).

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

66761172 is a wasteful number, since it uses less digits than its factorization.

66761172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5622 (or 5611 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 66761172 is about 8170.7510058746. The cubic root of 66761172 is about 405.6716427489.

The spelling of 66761172 in words is "sixty-six million, seven hundred sixty-one thousand, one hundred seventy-two".