66021543538 has 32 divisors (see below), whose sum is σ = 101084094720. Its totient is φ = 32333904000.

The previous prime is 66021543527. The next prime is 66021543547. The reversal of 66021543538 is 83534512066.

It is a super-3 number, since 3×66021543538³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 66021543494 and 66021543503.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13446628 + ... + 13451536.

It is an arithmetic number, because the mean of its divisors is an integer number (3158877960).

Almost surely, 2^66021543538 is an apocalyptic number.

66021543538 is a deficient number, since it is larger than the sum of its proper divisors (35062551182).

66021543538 is a wasteful number, since it uses less digits than its factorization.

66021543538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5602.

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 66021543538 in words is "sixty-six billion, twenty-one million, five hundred forty-three thousand, five hundred thirty-eight".