66501603 has 48 divisors (see below), whose sum is σ = 120047616. Its totient is φ = 34594560.

The previous prime is 66501599. The next prime is 66501623. The reversal of 66501603 is 30610566.

66501603 is a `hidden beast` number, since 6 + 6 + 50 + 1 + 603 = 666.

It is not a de Polignac number, because 66501603 - 2² = 66501599 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66501623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 32200 + ... + 34202.

It is an arithmetic number, because the mean of its divisors is an integer number (2500992).

Almost surely, 2^66501603 is an apocalyptic number.

66501603 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

66501603 is a deficient number, since it is larger than the sum of its proper divisors (53546013).

66501603 is a wasteful number, since it uses less digits than its factorization.

66501603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2064 (or 2061 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 66501603 is about 8154.8515007939. The cubic root of 66501603 is about 405.1452062772.

The spelling of 66501603 in words is "sixty-six million, five hundred one thousand, six hundred three".