66898439 has 4 divisors (see below), whose sum is σ = 67198656. Its totient is φ = 66598224.

The previous prime is 66898409. The next prime is 66898453. The reversal of 66898439 is 93489866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66898439 - 2¹² = 66894343 is a prime.

It is a super-2 number, since 2×66898439² = 8950802281273442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66898409) 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, 149774 + ... + 150219.

It is an arithmetic number, because the mean of its divisors is an integer number (16799664).

Almost surely, 2^66898439 is an apocalyptic number.

66898439 is a deficient number, since it is larger than the sum of its proper divisors (300217).

66898439 is a wasteful number, since it uses less digits than its factorization.

66898439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300216.

The product of its digits is 2239488, while the sum is 53.

The square root of 66898439 is about 8179.1465936245. The cubic root of 66898439 is about 405.9494849266.

The spelling of 66898439 in words is "sixty-six million, eight hundred ninety-eight thousand, four hundred thirty-nine".