66761817 has 16 divisors (see below), whose sum is σ = 94133760. Its totient is φ = 42019200.

The previous prime is 66761813. The next prime is 66761833. The reversal of 66761817 is 71816766.

It is not a de Polignac number, because 66761817 - 2² = 66761813 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66761813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4942 + ... + 12567.

It is an arithmetic number, because the mean of its divisors is an integer number (5883360).

Almost surely, 2^66761817 is an apocalyptic number.

It is an amenable number.

66761817 is a deficient number, since it is larger than the sum of its proper divisors (27371943).

66761817 is a wasteful number, since it uses less digits than its factorization.

66761817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17584.

The product of its digits is 84672, while the sum is 42.

The square root of 66761817 is about 8170.7904758352. The cubic root of 66761817 is about 405.6729491838.

The spelling of 66761817 in words is "sixty-six million, seven hundred sixty-one thousand, eight hundred seventeen".