66100501 has 2 divisors, whose sum is σ = 66100502. Its totient is φ = 66100500.

The previous prime is 66100499. The next prime is 66100511. The reversal of 66100501 is 10500166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61999876 + 4100625 = 7874^2 + 2025^2 .

It is a cyclic number.

It is not a de Polignac number, because 66100501 - 2¹ = 66100499 is a prime.

Together with 66100499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66100511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33050250 + 33050251.

It is an arithmetic number, because the mean of its divisors is an integer number (33050251).

Almost surely, 2^66100501 is an apocalyptic number.

It is an amenable number.

66100501 is a deficient number, since it is larger than the sum of its proper divisors (1).

66100501 is an equidigital number, since it uses as much as digits as its factorization.

66100501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 66100501 is about 8130.2214606983. The cubic root of 66100501 is about 404.3290236199.

Adding to 66100501 its reverse (10500166), we get a palindrome (76600667).

The spelling of 66100501 in words is "sixty-six million, one hundred thousand, five hundred one".