66556216031 has 2 divisors, whose sum is σ = 66556216032. Its totient is φ = 66556216030.

The previous prime is 66556215961. The next prime is 66556216039. The reversal of 66556216031 is 13061265566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66556216031 - 2²² = 66552021727 is a prime.

It is a super-2 number, since 2×66556216031² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66556216031.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66556216039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33278108015 + 33278108016.

It is an arithmetic number, because the mean of its divisors is an integer number (33278108016).

Almost surely, 2^66556216031 is an apocalyptic number.

66556216031 is a deficient number, since it is larger than the sum of its proper divisors (1).

66556216031 is an equidigital number, since it uses as much as digits as its factorization.

66556216031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 41.

The spelling of 66556216031 in words is "sixty-six billion, five hundred fifty-six million, two hundred sixteen thousand, thirty-one".