66540340 has 24 divisors (see below), whose sum is σ = 140149800. Its totient is φ = 26537088.

The previous prime is 66540323. The next prime is 66540347. The reversal of 66540340 is 4304566.

It can be written as a sum of positive squares in 4 ways, for example, as 4477456 + 62062884 = 2116^2 + 7878^2 .

It is a super-3 number, since 3×66540340³ (a number of 24 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66540299 and 66540308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66540347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2214 + ... + 11746.

It is an arithmetic number, because the mean of its divisors is an integer number (5839575).

Almost surely, 2^66540340 is an apocalyptic number.

It is an amenable number.

66540340 is an abundant number, since it is smaller than the sum of its proper divisors (73609460).

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

66540340 is a wasteful number, since it uses less digits than its factorization.

66540340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9891 (or 9889 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 66540340 is about 8157.2262442573. The cubic root of 66540340 is about 405.2238563291.

The spelling of 66540340 in words is "sixty-six million, five hundred forty thousand, three hundred forty".