66425381 has 4 divisors (see below), whose sum is σ = 72464064. Its totient is φ = 60386700.

The previous prime is 66425369. The next prime is 66425413. The reversal of 66425381 is 18352466.

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 not a de Polignac number, because 66425381 - 2¹⁰ = 66424357 is a prime.

It is a super-2 number, since 2×66425381² = 8824662481990322, 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 (66425321) 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, 3019325 + ... + 3019346.

It is an arithmetic number, because the mean of its divisors is an integer number (18116016).

Almost surely, 2^66425381 is an apocalyptic number.

It is an amenable number.

66425381 is a deficient number, since it is larger than the sum of its proper divisors (6038683).

66425381 is a wasteful number, since it uses less digits than its factorization.

66425381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6038682.

The product of its digits is 34560, while the sum is 35.

The square root of 66425381 is about 8150.1767465497. The cubic root of 66425381 is about 404.9903589637.

The spelling of 66425381 in words is "sixty-six million, four hundred twenty-five thousand, three hundred eighty-one".