66599421 has 32 divisors (see below), whose sum is σ = 112140288. Its totient is φ = 34256640.

The previous prime is 66599417. The next prime is 66599437. The reversal of 66599421 is 12499566.

It is a happy number.

It is not a de Polignac number, because 66599421 - 2² = 66599417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66599411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4156 + ... + 12266.

It is an arithmetic number, because the mean of its divisors is an integer number (3504384).

Almost surely, 2^66599421 is an apocalyptic number.

It is an amenable number.

66599421 is a deficient number, since it is larger than the sum of its proper divisors (45540867).

66599421 is a wasteful number, since it uses less digits than its factorization.

66599421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8161.

The product of its digits is 116640, while the sum is 42.

The square root of 66599421 is about 8160.8468310586. The cubic root of 66599421 is about 405.3437532639.

The spelling of 66599421 in words is "sixty-six million, five hundred ninety-nine thousand, four hundred twenty-one".