66206121 has 16 divisors (see below), whose sum is σ = 93156480. Its totient is φ = 41740160.

The previous prime is 66206093. The next prime is 66206131. The reversal of 66206121 is 12160266.

It is a cyclic number.

It is not a de Polignac number, because 66206121 - 2¹⁴ = 66189737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66206091 and 66206100.

It is not an unprimeable number, because it can be changed into a prime (66206131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 751 + ... + 11531.

It is an arithmetic number, because the mean of its divisors is an integer number (5822280).

Almost surely, 2^66206121 is an apocalyptic number.

It is an amenable number.

66206121 is a deficient number, since it is larger than the sum of its proper divisors (26950359).

66206121 is a wasteful number, since it uses less digits than its factorization.

66206121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10896.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 66206121 is about 8136.7143860406. The cubic root of 66206121 is about 404.5442640755.

Adding to 66206121 its reverse (12160266), we get a palindrome (78366387).

The spelling of 66206121 in words is "sixty-six million, two hundred six thousand, one hundred twenty-one".