66261457634 has 16 divisors (see below), whose sum is σ = 105243737400. Its totient is φ = 31180395264.

The previous prime is 66261457601. The next prime is 66261457637. The reversal of 66261457634 is 43675416266.

It can be written as a sum of positive squares in 4 ways, for example, as 62201856409 + 4059601225 = 249403^2 + 63715^2 .

It is not an unprimeable number, because it can be changed into a prime (66261457637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1108832 + ... + 1167060.

Almost surely, 2^66261457634 is an apocalyptic number.

66261457634 is a deficient number, since it is larger than the sum of its proper divisors (38982279766).

66261457634 is a wasteful number, since it uses less digits than its factorization.

66261457634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91717.

The product of its digits is 4354560, while the sum is 50.

The spelling of 66261457634 in words is "sixty-six billion, two hundred sixty-one million, four hundred fifty-seven thousand, six hundred thirty-four".