66354421 has 4 divisors (see below), whose sum is σ = 75833632. Its totient is φ = 56875212.

The previous prime is 66354413. The next prime is 66354427. The reversal of 66354421 is 12445366.

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 66354421 - 2³ = 66354413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66354427) 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, 4739595 + ... + 4739608.

It is an arithmetic number, because the mean of its divisors is an integer number (18958408).

Almost surely, 2^66354421 is an apocalyptic number.

It is an amenable number.

66354421 is a deficient number, since it is larger than the sum of its proper divisors (9479211).

66354421 is an equidigital number, since it uses as much as digits as its factorization.

66354421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9479210.

The product of its digits is 17280, while the sum is 31.

The square root of 66354421 is about 8145.8223034878. The cubic root of 66354421 is about 404.8460950552.

Adding to 66354421 its reverse (12445366), we get a palindrome (78799787).

The spelling of 66354421 in words is "sixty-six million, three hundred fifty-four thousand, four hundred twenty-one".