66401040 has 40 divisors (see below), whose sum is σ = 205843968. Its totient is φ = 17706880.

The previous prime is 66401011. The next prime is 66401053. The reversal of 66401040 is 4010466.

66401040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×66401040² = 8818196226163200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66400998 and 66401016.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138096 + ... + 138575.

Almost surely, 2^66401040 is an apocalyptic number.

66401040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66401040 is an abundant number, since it is smaller than the sum of its proper divisors (139442928).

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

66401040 is a wasteful number, since it uses less digits than its factorization.

66401040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276687 (or 276681 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 66401040 is about 8148.6833292256. The cubic root of 66401040 is about 404.9408845282.

It can be divided in two parts, 6 and 6401040, that added together give a palindrome (6401046).

The spelling of 66401040 in words is "sixty-six million, four hundred one thousand, forty".