66238906889 has 4 divisors (see below), whose sum is σ = 66241837056. Its totient is φ = 66235976724.

The previous prime is 66238906843. The next prime is 66238906901. The reversal of 66238906889 is 98860983266.

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 not a de Polignac number, because 66238906889 - 2²⁸ = 65970471433 is a prime.

It is a super-2 number, since 2×66238906889² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66238906819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1430909 + ... + 1476474.

It is an arithmetic number, because the mean of its divisors is an integer number (16560459264).

Almost surely, 2^66238906889 is an apocalyptic number.

It is an amenable number.

66238906889 is a deficient number, since it is larger than the sum of its proper divisors (2930167).

66238906889 is a wasteful number, since it uses less digits than its factorization.

66238906889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2930166.

The product of its (nonzero) digits is 53747712, while the sum is 65.

The spelling of 66238906889 in words is "sixty-six billion, two hundred thirty-eight million, nine hundred six thousand, eight hundred eighty-nine".