66901640 has 32 divisors (see below), whose sum is σ = 162109080. Its totient is φ = 24701952.

The previous prime is 66901631. The next prime is 66901649. The reversal of 66901640 is 4610966.

It is an interprime number because it is at equal distance from previous prime (66901631) and next prime (66901649).

It can be written as a sum of positive squares in 4 ways, for example, as 36409156 + 30492484 = 6034^2 + 5522^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66901597 and 66901606.

It is not an unprimeable number, because it can be changed into a prime (66901649) 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, 63809 + ... + 64848.

Almost surely, 2^66901640 is an apocalyptic number.

It is an amenable number.

66901640 is an abundant number, since it is smaller than the sum of its proper divisors (95207440).

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

66901640 is a wasteful number, since it uses less digits than its factorization.

66901640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128681 (or 128677 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 66901640 is about 8179.3422718456. The cubic root of 66901640 is about 405.9559595349.

The spelling of 66901640 in words is "sixty-six million, nine hundred one thousand, six hundred forty".