66245081021 has 20 divisors (see below), whose sum is σ = 77351698944. Its totient is φ = 56729799000.

The previous prime is 66245080981. The next prime is 66245081029. The reversal of 66245081021 is 12018054266.

It is not a de Polignac number, because 66245081021 - 2¹⁴ = 66245064637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66245081029) 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 19 ways as a sum of consecutive naturals, for example, 2751566 + ... + 2775536.

Almost surely, 2^66245081021 is an apocalyptic number.

It is an amenable number.

66245081021 is a deficient number, since it is larger than the sum of its proper divisors (11106617923).

66245081021 is an equidigital number, since it uses as much as digits as its factorization.

66245081021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25150 (or 25129 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The spelling of 66245081021 in words is "sixty-six billion, two hundred forty-five million, eighty-one thousand, twenty-one".