64640662042220 has 96 divisors (see below), whose sum is σ = 152209993320000. Its totient is φ = 22852091658240.

The previous prime is 64640662042211. The next prime is 64640662042241. The reversal of 64640662042220 is 2224026604646.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (44).

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, 6987872 + ... + 13345848.

It is an arithmetic number, because the mean of its divisors is an integer number (1585520763750).

Almost surely, 2^{64640662042220} 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 64640662042220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76104996660000).

64640662042220 is an abundant number, since it is smaller than the sum of its proper divisors (87569331277780).

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

64640662042220 is a wasteful number, since it uses less digits than its factorization.

64640662042220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6359283 (or 6359281 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 44.

Adding to 64640662042220 its reverse (2224026604646), we get a palindrome (66864688646866).

It can be divided in two parts, 646406 and 62042220, that added together give a palindrome (62688626).

The spelling of 64640662042220 in words is "sixty-four trillion, six hundred forty billion, six hundred sixty-two million, forty-two thousand, two hundred twenty".