66503403025138 has 16 divisors (see below), whose sum is σ = 99993089668824. Its totient is φ = 33172443496960.

The previous prime is 66503403025099. The next prime is 66503403025139. The reversal of 66503403025138 is 83152030430566.

It can be written as a sum of positive squares in 4 ways, for example, as 64274004649449 + 2229398375689 = 8017107^2 + 1493117^2 .

It is a super-2 number, since 2×66503403025138² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66503403025139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15698773 + ... + 19479688.

Almost surely, 2^{66503403025138} is an apocalyptic number.

66503403025138 is a deficient number, since it is larger than the sum of its proper divisors (33489686643686).

66503403025138 is a wasteful number, since it uses less digits than its factorization.

66503403025138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35180717.

The product of its (nonzero) digits is 1555200, while the sum is 46.

The spelling of 66503403025138 in words is "sixty-six trillion, five hundred three billion, four hundred three million, twenty-five thousand, one hundred thirty-eight".