640660521226000 has 160 divisors (see below), whose sum is σ = 1689995608644096. Its totient is φ = 232960619520000.

The previous prime is 640660521225997. The next prime is 640660521226003. The reversal of 640660521226000 is 622125066046.

It is an interprime number because it is at equal distance from previous prime (640660521225997) and next prime (640660521226003).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (640660521226003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 781052089 + ... + 781871911.

Almost surely, 2^{640660521226000} 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 640660521226000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (844997804322048).

640660521226000 is an abundant number, since it is smaller than the sum of its proper divisors (1049335087418096).

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

640660521226000 is a wasteful number, since it uses less digits than its factorization.

640660521226000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855378 (or 855362 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 640660521226000 in words is "six hundred forty trillion, six hundred sixty billion, five hundred twenty-one million, two hundred twenty-six thousand".