66220761 has 4 divisors (see below), whose sum is σ = 88294352. Its totient is φ = 44147172.

The previous prime is 66220753. The next prime is 66220769. The reversal of 66220761 is 16702266.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (66220753) and next prime (66220769).

It is not a de Polignac number, because 66220761 - 2³ = 66220753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66220769) 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, 11036791 + ... + 11036796.

It is an arithmetic number, because the mean of its divisors is an integer number (22073588).

Almost surely, 2^66220761 is an apocalyptic number.

It is an amenable number.

66220761 is a deficient number, since it is larger than the sum of its proper divisors (22073591).

66220761 is a wasteful number, since it uses less digits than its factorization.

66220761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22073590.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 66220761 is about 8137.6139623356. The cubic root of 66220761 is about 404.5740805106.

The spelling of 66220761 in words is "sixty-six million, two hundred twenty thousand, seven hundred sixty-one".