73217640 has 128 divisors (see below), whose sum is σ = 244944000. Its totient is φ = 17399808.

The previous prime is 73217597. The next prime is 73217647. The reversal of 73217640 is 4671237.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 73217598 and 73217607.

It is not an unprimeable number, because it can be changed into a prime (73217647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37816 + ... + 39704.

It is an arithmetic number, because the mean of its divisors is an integer number (1913625).

Almost surely, 2^73217640 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 73217640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122472000).

73217640 is an abundant number, since it is smaller than the sum of its proper divisors (171726360).

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

73217640 is a wasteful number, since it uses less digits than its factorization.

73217640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939 (or 1935 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 73217640 is about 8556.7306840872. The cubic root of 73217640 is about 418.3488460921.

Adding to 73217640 its reverse (4671237), we get a palindrome (77888877).

The spelling of 73217640 in words is "seventy-three million, two hundred seventeen thousand, six hundred forty".