66251621060 has 48 divisors (see below), whose sum is σ = 147337599024. Its totient is φ = 24937525248.

The previous prime is 66251620991. The next prime is 66251621063. The reversal of 66251621060 is 6012615266.

It can be written as a sum of positive squares in 8 ways, for example, as 3327905344 + 62923715716 = 57688^2 + 250846^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66251621060.

It is not an unprimeable number, because it can be changed into a prime (66251621063) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2563322 + ... + 2589038.

It is an arithmetic number, because the mean of its divisors is an integer number (3069533313).

Almost surely, 2^66251621060 is an apocalyptic number.

It is an amenable number.

66251621060 is an abundant number, since it is smaller than the sum of its proper divisors (81085977964).

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

66251621060 is a wasteful number, since it uses less digits than its factorization.

66251621060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33320 (or 33318 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 66251621060 in words is "sixty-six billion, two hundred fifty-one million, six hundred twenty-one thousand, sixty".