66645031 has 2 divisors, whose sum is σ = 66645032. Its totient is φ = 66645030.

The previous prime is 66644999. The next prime is 66645041. The reversal of 66645031 is 13054666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66645031 - 2⁵ = 66644999 is a prime.

It is a super-2 number, since 2×66645031² = 8883120313981922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66644984 and 66645002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66645041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33322515 + 33322516.

It is an arithmetic number, because the mean of its divisors is an integer number (33322516).

Almost surely, 2^66645031 is an apocalyptic number.

66645031 is a deficient number, since it is larger than the sum of its proper divisors (1).

66645031 is an equidigital number, since it uses as much as digits as its factorization.

66645031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 66645031 is about 8163.6407931756. The cubic root of 66645031 is about 405.4362641272.

Adding to 66645031 its reverse (13054666), we get a palindrome (79699697).

The spelling of 66645031 in words is "sixty-six million, six hundred forty-five thousand, thirty-one".