73661640 has 128 divisors (see below), whose sum is σ = 248451840. Its totient is φ = 17335296.

The previous prime is 73661639. The next prime is 73661657. The reversal of 73661640 is 4616637.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34854 + ... + 36906.

It is an arithmetic number, because the mean of its divisors is an integer number (1941030).

Almost surely, 2^73661640 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 73661640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124225920).

73661640 is an abundant number, since it is smaller than the sum of its proper divisors (174790200).

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

73661640 is a wasteful number, since it uses less digits than its factorization.

73661640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2103 (or 2099 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 73661640 is about 8582.6359587250. The cubic root of 73661640 is about 419.1927806237.

The spelling of 73661640 in words is "seventy-three million, six hundred sixty-one thousand, six hundred forty".