66775420031 has 4 divisors (see below), whose sum is σ = 67114381752. Its totient is φ = 66436458312.

The previous prime is 66775420027. The next prime is 66775420069. The reversal of 66775420031 is 13002457766.

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 66775420031 - 2² = 66775420027 is a prime.

It is a super-2 number, since 2×66775420031² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66775420531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169480565 + ... + 169480958.

It is an arithmetic number, because the mean of its divisors is an integer number (16778595438).

Almost surely, 2^66775420031 is an apocalyptic number.

66775420031 is a deficient number, since it is larger than the sum of its proper divisors (338961721).

66775420031 is a wasteful number, since it uses less digits than its factorization.

66775420031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338961720.

The product of its (nonzero) digits is 211680, while the sum is 41.

Adding to 66775420031 its reverse (13002457766), we get a palindrome (79777877797).

The spelling of 66775420031 in words is "sixty-six billion, seven hundred seventy-five million, four hundred twenty thousand, thirty-one".