640221321251450 has 24 divisors (see below), whose sum is σ = 1190814795981120. Its totient is φ = 256087853564400.

The previous prime is 640221321251443. The next prime is 640221321251507. The reversal of 640221321251450 is 54152123122046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2508041 + ... + 35871059.

It is an arithmetic number, because the mean of its divisors is an integer number (49617283165880).

Almost surely, 2^{640221321251450} is an apocalyptic number.

640221321251450 is a deficient number, since it is larger than the sum of its proper divisors (550593474729670).

640221321251450 is a wasteful number, since it uses less digits than its factorization.

640221321251450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33746822 (or 33746817 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 38.

Adding to 640221321251450 its reverse (54152123122046), we get a palindrome (694373444373496).

The spelling of 640221321251450 in words is "six hundred forty trillion, two hundred twenty-one billion, three hundred twenty-one million, two hundred fifty-one thousand, four hundred fifty".