66361840 has 40 divisors (see below), whose sum is σ = 155177568. Its totient is φ = 26392320.

The previous prime is 66361837. The next prime is 66361853. The reversal of 66361840 is 4816366.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 66361796 and 66361805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12189 + ... + 16771.

Almost surely, 2^66361840 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 66361840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77588784).

66361840 is an abundant number, since it is smaller than the sum of its proper divisors (88815728).

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

66361840 is a wasteful number, since it uses less digits than its factorization.

66361840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4777 (or 4771 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 66361840 is about 8146.2776775654. The cubic root of 66361840 is about 404.8611829282.

The spelling of 66361840 in words is "sixty-six million, three hundred sixty-one thousand, eight hundred forty".