66531001 has 4 divisors (see below), whose sum is σ = 66570832. Its totient is φ = 66491172.

The previous prime is 66530999. The next prime is 66531011. The reversal of 66531001 is 10013566.

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 66531001 - 2¹ = 66530999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66531011) 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, 17295 + ... + 20788.

It is an arithmetic number, because the mean of its divisors is an integer number (16642708).

Almost surely, 2^66531001 is an apocalyptic number.

It is an amenable number.

66531001 is a deficient number, since it is larger than the sum of its proper divisors (39831).

66531001 is a wasteful number, since it uses less digits than its factorization.

66531001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39830.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 66531001 is about 8156.6537869398. The cubic root of 66531001 is about 405.2048975909.

Adding to 66531001 its reverse (10013566), we get a palindrome (76544567).

The spelling of 66531001 in words is "sixty-six million, five hundred thirty-one thousand, one".