66540167638 has 64 divisors (see below), whose sum is σ = 117965030400. Its totient is φ = 27557429760.

The previous prime is 66540167623. The next prime is 66540167663. The reversal of 66540167638 is 83676104566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51620898 + ... + 51622186.

It is an arithmetic number, because the mean of its divisors is an integer number (1843203600).

Almost surely, 2^66540167638 is an apocalyptic number.

66540167638 is a deficient number, since it is larger than the sum of its proper divisors (51424862762).

66540167638 is a wasteful number, since it uses less digits than its factorization.

66540167638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2125.

The product of its (nonzero) digits is 4354560, while the sum is 52.

The spelling of 66540167638 in words is "sixty-six billion, five hundred forty million, one hundred sixty-seven thousand, six hundred thirty-eight".