66251501 has 2 divisors, whose sum is σ = 66251502. Its totient is φ = 66251500.

The previous prime is 66251489. The next prime is 66251503. The reversal of 66251501 is 10515266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45549001 + 20702500 = 6749^2 + 4550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66251501 is a prime.

It is a super-2 number, since 2×66251501² = 8778522769506002, which contains 22 as substring.

Together with 66251503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66251503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33125750 + 33125751.

It is an arithmetic number, because the mean of its divisors is an integer number (33125751).

Almost surely, 2^66251501 is an apocalyptic number.

It is an amenable number.

66251501 is a deficient number, since it is larger than the sum of its proper divisors (1).

66251501 is an equidigital number, since it uses as much as digits as its factorization.

66251501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 66251501 is about 8139.5025032246. The cubic root of 66251501 is about 404.6366725798.

Adding to 66251501 its reverse (10515266), we get a palindrome (76766767).

The spelling of 66251501 in words is "sixty-six million, two hundred fifty-one thousand, five hundred one".