66513538 has 32 divisors (see below), whose sum is σ = 126766080. Its totient is φ = 25462080.

The previous prime is 66513533. The next prime is 66513619. The reversal of 66513538 is 83531566.

It is a junction number, because it is equal to n+sod(n) for n = 66513497 and 66513506.

It is not an unprimeable number, because it can be changed into a prime (66513533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253 + ... + 11536.

It is an arithmetic number, because the mean of its divisors is an integer number (3961440).

Almost surely, 2^66513538 is an apocalyptic number.

66513538 is a deficient number, since it is larger than the sum of its proper divisors (60252542).

66513538 is a wasteful number, since it uses less digits than its factorization.

66513538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11842.

The product of its digits is 64800, while the sum is 37.

The square root of 66513538 is about 8155.5832409460. The cubic root of 66513538 is about 405.1694418774.

The spelling of 66513538 in words is "sixty-six million, five hundred thirteen thousand, five hundred thirty-eight".