66820501 has 4 divisors (see below), whose sum is σ = 72895104. Its totient is φ = 60745900.

The previous prime is 66820441. The next prime is 66820513. The reversal of 66820501 is 10502866.

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 66820501 - 2⁹ = 66819989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66820501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66820571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3037285 + ... + 3037306.

It is an arithmetic number, because the mean of its divisors is an integer number (18223776).

Almost surely, 2^66820501 is an apocalyptic number.

It is an amenable number.

66820501 is a deficient number, since it is larger than the sum of its proper divisors (6074603).

66820501 is a wasteful number, since it uses less digits than its factorization.

66820501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6074602.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 66820501 is about 8174.3807716548. The cubic root of 66820501 is about 405.7917772828.

The spelling of 66820501 in words is "sixty-six million, eight hundred twenty thousand, five hundred one".