66890951 has 2 divisors, whose sum is σ = 66890952. Its totient is φ = 66890950.

The previous prime is 66890939. The next prime is 66890977. The reversal of 66890951 is 15909866.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66890951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66890651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33445475 + 33445476.

It is an arithmetic number, because the mean of its divisors is an integer number (33445476).

Almost surely, 2^66890951 is an apocalyptic number.

66890951 is a deficient number, since it is larger than the sum of its proper divisors (1).

66890951 is an equidigital number, since it uses as much as digits as its factorization.

66890951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 66890951 is about 8178.6888313470. The cubic root of 66890951 is about 405.9343382694.

It can be divided in two parts, 668 and 90951, that added together give a palindrome (91619).

The spelling of 66890951 in words is "sixty-six million, eight hundred ninety thousand, nine hundred fifty-one".