66131251 has 2 divisors, whose sum is σ = 66131252. Its totient is φ = 66131250.

The previous prime is 66131249. The next prime is 66131287. The reversal of 66131251 is 15213166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66131251 - 2¹ = 66131249 is a prime.

Together with 66131249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66131201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33065625 + 33065626.

It is an arithmetic number, because the mean of its divisors is an integer number (33065626).

Almost surely, 2^66131251 is an apocalyptic number.

66131251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66131251 is an equidigital number, since it uses as much as digits as its factorization.

66131251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 25.

The square root of 66131251 is about 8132.1123332133. The cubic root of 66131251 is about 404.3917119497.

The spelling of 66131251 in words is "sixty-six million, one hundred thirty-one thousand, two hundred fifty-one".