66126466640 has 40 divisors (see below), whose sum is σ = 165570501768. Its totient is φ = 24415925760.

The previous prime is 66126466621. The next prime is 66126466697. The reversal of 66126466640 is 4666462166.

It can be written as a sum of positive squares in 4 ways, for example, as 9446284864 + 56680181776 = 97192^2 + 238076^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 31790531 + ... + 31792610.

Almost surely, 2^66126466640 is an apocalyptic number.

It is an amenable number.

66126466640 is an abundant number, since it is smaller than the sum of its proper divisors (99444035128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66126466640 is a wasteful number, since it uses less digits than its factorization.

66126466640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63583167 (or 63583161 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 47.

The spelling of 66126466640 in words is "sixty-six billion, one hundred twenty-six million, four hundred sixty-six thousand, six hundred forty".