640229473600 has 168 divisors, whose sum is σ = 1630704612600. Its totient is φ = 247106764800.

The previous prime is 640229473589. The next prime is 640229473603. The reversal of 640229473600 is 6374922046.

It can be written as a sum of positive squares in 12 ways, for example, as 84095360064 + 556134113536 = 289992^2 + 745744^2 .

It is a super-2 number, since 2×640229473600² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640229473603) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 98782360 + ... + 98788840.

It is an arithmetic number, because the mean of its divisors is an integer number (9706575075).

Almost surely, 2^640229473600 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 640229473600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815352306300).

640229473600 is an abundant number, since it is smaller than the sum of its proper divisors (990475139000).

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

640229473600 is a wasteful number, since it uses less digits than its factorization.

640229473600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8661 (or 8646 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 43.

The spelling of 640229473600 in words is "six hundred forty billion, two hundred twenty-nine million, four hundred seventy-three thousand, six hundred".