66503973 has 4 divisors (see below), whose sum is σ = 88671968. Its totient is φ = 44335980.

The previous prime is 66503953. The next prime is 66503977. The reversal of 66503973 is 37930566.

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 not a de Polignac number, because 66503973 - 2⁹ = 66503461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66503977) 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, 11083993 + ... + 11083998.

It is an arithmetic number, because the mean of its divisors is an integer number (22167992).

Almost surely, 2^66503973 is an apocalyptic number.

It is an amenable number.

66503973 is a deficient number, since it is larger than the sum of its proper divisors (22167995).

66503973 is a wasteful number, since it uses less digits than its factorization.

66503973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22167994.

The product of its (nonzero) digits is 102060, while the sum is 39.

The square root of 66503973 is about 8154.9968117713. The cubic root of 66503973 is about 405.1500191072.

It can be divided in two parts, 66503 and 973, that added together give a palindrome (67476).

The spelling of 66503973 in words is "sixty-six million, five hundred three thousand, nine hundred seventy-three".