640073228 has 6 divisors (see below), whose sum is σ = 1120128156. Its totient is φ = 320036612.

The previous prime is 640073227. The next prime is 640073243. The reversal of 640073228 is 822370046.

It is a junction number, because it is equal to n+sod(n) for n = 640073194 and 640073203.

It is not an unprimeable number, because it can be changed into a prime (640073227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80009150 + ... + 80009157.

It is an arithmetic number, because the mean of its divisors is an integer number (186688026).

Almost surely, 2^640073228 is an apocalyptic number.

It is an amenable number.

640073228 is a deficient number, since it is larger than the sum of its proper divisors (480054928).

640073228 is a wasteful number, since it uses less digits than its factorization.

640073228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160018311 (or 160018309 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 640073228 is about 25299.6685353781. The cubic root of 640073228 is about 861.8067424558.

The spelling of 640073228 in words is "six hundred forty million, seventy-three thousand, two hundred twenty-eight".