66551761 has 8 divisors (see below), whose sum is σ = 68816384. Its totient is φ = 64294560.

The previous prime is 66551747. The next prime is 66551777. The reversal of 66551761 is 16715566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66551761 - 2¹⁷ = 66420689 is a prime.

It is a super-2 number, since 2×66551761² = 8858273784402242, 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 66551761.

It is not an unprimeable number, because it can be changed into a prime (66551731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21061 + ... + 24013.

It is an arithmetic number, because the mean of its divisors is an integer number (8602048).

Almost surely, 2^66551761 is an apocalyptic number.

It is an amenable number.

66551761 is a deficient number, since it is larger than the sum of its proper divisors (2264623).

66551761 is a wasteful number, since it uses less digits than its factorization.

66551761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3711.

The product of its digits is 37800, while the sum is 37.

The square root of 66551761 is about 8157.9262683601. The cubic root of 66551761 is about 405.2470392429.

The spelling of 66551761 in words is "sixty-six million, five hundred fifty-one thousand, seven hundred sixty-one".