66398251842 has 96 divisors (see below), whose sum is σ = 156173799600. Its totient is φ = 20266799616.

The previous prime is 66398251831. The next prime is 66398251853. The reversal of 66398251842 is 24815289366.

66398251842 is a `hidden beast` number, since 6 + 6 + 3 + 9 + 82 + 518 + 42 = 666.

It is an interprime number because it is at equal distance from previous prime (66398251831) and next prime (66398251853).

It can be written as a sum of positive squares in 8 ways, for example, as 65941617681 + 456634161 = 256791^2 + 21369^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15698584 + ... + 15702812.

Almost surely, 2^66398251842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66398251842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78086899800).

66398251842 is an abundant number, since it is smaller than the sum of its proper divisors (89775547758).

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

66398251842 is a wasteful number, since it uses less digits than its factorization.

66398251842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4772 (or 4769 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The spelling of 66398251842 in words is "sixty-six billion, three hundred ninety-eight million, two hundred fifty-one thousand, eight hundred forty-two".