66899951 has 2 divisors, whose sum is σ = 66899952. Its totient is φ = 66899950.

The previous prime is 66899933. The next prime is 66899983. The reversal of 66899951 is 15999866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66899951 - 2⁶ = 66899887 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 66899893 and 66899902.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66890951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33449975 + 33449976.

It is an arithmetic number, because the mean of its divisors is an integer number (33449976).

Almost surely, 2^66899951 is an apocalyptic number.

66899951 is a deficient number, since it is larger than the sum of its proper divisors (1).

66899951 is an equidigital number, since it uses as much as digits as its factorization.

66899951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1049760, while the sum is 53.

The square root of 66899951 is about 8179.2390232833. The cubic root of 66899951 is about 405.9525432490.

The spelling of 66899951 in words is "sixty-six million, eight hundred ninety-nine thousand, nine hundred fifty-one".