67641640 has 64 divisors (see below), whose sum is σ = 175815360. Its totient is φ = 23147520.

The previous prime is 67641631. The next prime is 67641641. The reversal of 67641640 is 4614676.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 67641596 and 67641605.

It is not an unprimeable number, because it can be changed into a prime (67641641) 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, 2959 + ... + 12001.

It is an arithmetic number, because the mean of its divisors is an integer number (2747115).

Almost surely, 2^67641640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 67641640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87907680).

67641640 is an abundant number, since it is smaller than the sum of its proper divisors (108173720).

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

67641640 is a wasteful number, since it uses less digits than its factorization.

67641640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9082 (or 9078 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 67641640 is about 8224.4537812550. The cubic root of 67641640 is about 407.4472361959.

The spelling of 67641640 in words is "sixty-seven million, six hundred forty-one thousand, six hundred forty".