66061331 has 4 divisors (see below), whose sum is σ = 75498672. Its totient is φ = 56623992.

The previous prime is 66061327. The next prime is 66061339. The reversal of 66061331 is 13316066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66061331 - 2² = 66061327 is a prime.

It is a super-2 number, since 2×66061331² = 8728198906983122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66061331.

It is not an unprimeable number, because it can be changed into a prime (66061339) 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, 4718660 + ... + 4718673.

It is an arithmetic number, because the mean of its divisors is an integer number (18874668).

Almost surely, 2^66061331 is an apocalyptic number.

66061331 is a deficient number, since it is larger than the sum of its proper divisors (9437341).

66061331 is an equidigital number, since it uses as much as digits as its factorization.

66061331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9437340.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 66061331 is about 8127.8121902514. The cubic root of 66061331 is about 404.2491417380.

Adding to 66061331 its reverse (13316066), we get a palindrome (79377397).

The spelling of 66061331 in words is "sixty-six million, sixty-one thousand, three hundred thirty-one".