66626531 has 2 divisors, whose sum is σ = 66626532. Its totient is φ = 66626530.

The previous prime is 66626513. The next prime is 66626537. The reversal of 66626531 is 13562666.

Together with previous prime (66626513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66626531 - 2¹⁴ = 66610147 is a prime.

It is a super-2 number, since 2×66626531² = 8878189266187922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 66626491 and 66626500.

It is not a weakly prime, because it can be changed into another prime (66626537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33313265 + 33313266.

It is an arithmetic number, because the mean of its divisors is an integer number (33313266).

Almost surely, 2^66626531 is an apocalyptic number.

66626531 is a deficient number, since it is larger than the sum of its proper divisors (1).

66626531 is an equidigital number, since it uses as much as digits as its factorization.

66626531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 35.

The square root of 66626531 is about 8162.5076416503. The cubic root of 66626531 is about 405.3987456261.

The spelling of 66626531 in words is "sixty-six million, six hundred twenty-six thousand, five hundred thirty-one".