66447798 has 32 divisors (see below), whose sum is σ = 144154080. Its totient is φ = 20336640.

The previous prime is 66447791. The next prime is 66447803. The reversal of 66447798 is 89774466.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 66447798.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66447791) 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, 3763 + ... + 12126.

It is an arithmetic number, because the mean of its divisors is an integer number (4504815).

Almost surely, 2^66447798 is an apocalyptic number.

66447798 is an abundant number, since it is smaller than the sum of its proper divisors (77706282).

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

66447798 is a wasteful number, since it uses less digits than its factorization.

66447798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15952.

The product of its digits is 2032128, while the sum is 51.

The square root of 66447798 is about 8151.5518767901. The cubic root of 66447798 is about 405.0359120723.

The spelling of 66447798 in words is "sixty-six million, four hundred forty-seven thousand, seven hundred ninety-eight".