66957640 has 16 divisors (see below), whose sum is σ = 150654780. Its totient is φ = 26783040.

The previous prime is 66957617. The next prime is 66957643. The reversal of 66957640 is 4675966.

It can be written as a sum of positive squares in 2 ways, for example, as 65512836 + 1444804 = 8094^2 + 1202^2 .

It is not an unprimeable number, because it can be changed into a prime (66957643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 836931 + ... + 837010.

Almost surely, 2^66957640 is an apocalyptic number.

It is an amenable number.

66957640 is an abundant number, since it is smaller than the sum of its proper divisors (83697140).

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

66957640 is a wasteful number, since it uses less digits than its factorization.

66957640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673952 (or 1673948 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 66957640 is about 8182.7648139244. The cubic root of 66957640 is about 406.0691963886.

The spelling of 66957640 in words is "sixty-six million, nine hundred fifty-seven thousand, six hundred forty".