66556001 has 4 divisors (see below), whose sum is σ = 67080192. Its totient is φ = 66031812.

The previous prime is 66555971. The next prime is 66556027. The reversal of 66556001 is 10065566.

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 66556001 - 2¹⁰ = 66554977 is a prime.

It is a super-2 number, since 2×66556001² = 8859402538224002, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66556201) 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, 261905 + ... + 262158.

It is an arithmetic number, because the mean of its divisors is an integer number (16770048).

Almost surely, 2^66556001 is an apocalyptic number.

It is an amenable number.

66556001 is a deficient number, since it is larger than the sum of its proper divisors (524191).

66556001 is a wasteful number, since it uses less digits than its factorization.

66556001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524190.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 66556001 is about 8158.1861341845. The cubic root of 66556001 is about 405.2556451306.

The spelling of 66556001 in words is "sixty-six million, five hundred fifty-six thousand, one".