66138851 has 2 divisors, whose sum is σ = 66138852. Its totient is φ = 66138850.

The previous prime is 66138833. The next prime is 66138871. The reversal of 66138851 is 15883166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66138851 is a prime.

It is a super-2 number, since 2×66138851² = 8748695223200402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66138811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33069425 + 33069426.

It is an arithmetic number, because the mean of its divisors is an integer number (33069426).

Almost surely, 2^66138851 is an apocalyptic number.

66138851 is a deficient number, since it is larger than the sum of its proper divisors (1).

66138851 is an equidigital number, since it uses as much as digits as its factorization.

66138851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 38.

The square root of 66138851 is about 8132.5796030534. The cubic root of 66138851 is about 404.4072026556.

The spelling of 66138851 in words is "sixty-six million, one hundred thirty-eight thousand, eight hundred fifty-one".