66126121 has 4 divisors (see below), whose sum is σ = 66164992. Its totient is φ = 66087252.

The previous prime is 66126097. The next prime is 66126143. The reversal of 66126121 is 12162166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66126121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66126191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16761 + ... + 20326.

It is an arithmetic number, because the mean of its divisors is an integer number (16541248).

Almost surely, 2^66126121 is an apocalyptic number.

It is an amenable number.

66126121 is a deficient number, since it is larger than the sum of its proper divisors (38871).

66126121 is a wasteful number, since it uses less digits than its factorization.

66126121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38870.

The product of its digits is 864, while the sum is 25.

The square root of 66126121 is about 8131.7969108925. The cubic root of 66126121 is about 404.3812550522.

Adding to 66126121 its reverse (12162166), we get a palindrome (78288287).

The spelling of 66126121 in words is "sixty-six million, one hundred twenty-six thousand, one hundred twenty-one".