66121031 has 2 divisors, whose sum is σ = 66121032. Its totient is φ = 66121030.

The previous prime is 66120959. The next prime is 66121039. The reversal of 66121031 is 13012166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66121031 - 2¹⁰ = 66120007 is a prime.

It is a super-2 number, since 2×66121031² = 8743981481005922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66120994 and 66121012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66121039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33060515 + 33060516.

It is an arithmetic number, because the mean of its divisors is an integer number (33060516).

Almost surely, 2^66121031 is an apocalyptic number.

66121031 is a deficient number, since it is larger than the sum of its proper divisors (1).

66121031 is an equidigital number, since it uses as much as digits as its factorization.

66121031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 66121031 is about 8131.4839359123. The cubic root of 66121031 is about 404.3708791555.

Adding to 66121031 its reverse (13012166), we get a palindrome (79133197).

The spelling of 66121031 in words is "sixty-six million, one hundred twenty-one thousand, thirty-one".