66156217031 has 2 divisors, whose sum is σ = 66156217032. Its totient is φ = 66156217030.

The previous prime is 66156216961. The next prime is 66156217037. The reversal of 66156217031 is 13071265166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66156217031 - 2¹⁴ = 66156200647 is a prime.

It is a super-2 number, since 2×66156217031² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66156217037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33078108515 + 33078108516.

It is an arithmetic number, because the mean of its divisors is an integer number (33078108516).

Almost surely, 2^66156217031 is an apocalyptic number.

66156217031 is a deficient number, since it is larger than the sum of its proper divisors (1).

66156217031 is an equidigital number, since it uses as much as digits as its factorization.

66156217031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 38.

The spelling of 66156217031 in words is "sixty-six billion, one hundred fifty-six million, two hundred seventeen thousand, thirty-one".