66642285456820 has 24 divisors (see below), whose sum is σ = 142320813012000. Its totient is φ = 26205102077472.

The previous prime is 66642285456781. The next prime is 66642285456853. The reversal of 66642285456820 is 2865458224666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28238255370 + ... + 28238257729.

It is an arithmetic number, because the mean of its divisors is an integer number (5930033875500).

Almost surely, 2^{66642285456820} is an apocalyptic number.

It is an amenable number.

66642285456820 is an abundant number, since it is smaller than the sum of its proper divisors (75678527555180).

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

66642285456820 is a wasteful number, since it uses less digits than its factorization.

66642285456820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56476513167 (or 56476513165 counting only the distinct ones).

The product of its (nonzero) digits is 265420800, while the sum is 64.

The spelling of 66642285456820 in words is "sixty-six trillion, six hundred forty-two billion, two hundred eighty-five million, four hundred fifty-six thousand, eight hundred twenty".