66251620020 has 48 divisors (see below), whose sum is σ = 185619813120. Its totient is φ = 17656119936.

The previous prime is 66251620013. The next prime is 66251620021. The reversal of 66251620020 is 2002615266.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 66251620020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66251620021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 245500 + ... + 439059.

It is an arithmetic number, because the mean of its divisors is an integer number (3867079440).

Almost surely, 2^66251620020 is an apocalyptic number.

66251620020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66251620020 is an abundant number, since it is smaller than the sum of its proper divisors (119368193100).

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

66251620020 is a wasteful number, since it uses less digits than its factorization.

66251620020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686184 (or 686182 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 66251620020 in words is "sixty-six billion, two hundred fifty-one million, six hundred twenty thousand, twenty".