66424397 has 4 divisors (see below), whose sum is σ = 71533980. Its totient is φ = 61314816.

The previous prime is 66424381. The next prime is 66424411. The reversal of 66424397 is 79342466.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8375236 + 58049161 = 2894^2 + 7619^2 .

It is a cyclic number.

It is not a de Polignac number, because 66424397 - 2⁴ = 66424381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66424307) 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, 2554772 + ... + 2554797.

It is an arithmetic number, because the mean of its divisors is an integer number (17883495).

Almost surely, 2^66424397 is an apocalyptic number.

It is an amenable number.

66424397 is a deficient number, since it is larger than the sum of its proper divisors (5109583).

66424397 is a wasteful number, since it uses less digits than its factorization.

66424397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5109582.

The product of its digits is 217728, while the sum is 41.

The square root of 66424397 is about 8150.1163795372. The cubic root of 66424397 is about 404.9883591635.

The spelling of 66424397 in words is "sixty-six million, four hundred twenty-four thousand, three hundred ninety-seven".