640200262021 has 4 divisors (see below), whose sum is σ = 640950790732. Its totient is φ = 639449733312.

The previous prime is 640200262003. The next prime is 640200262049. The reversal of 640200262021 is 120262002046.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 115175390625 + 525024871396 = 339375^2 + 724586^2 .

It is a cyclic number.

It is not a de Polignac number, because 640200262021 - 2⁷ = 640200261893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640200265021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375263076 + ... + 375264781.

It is an arithmetic number, because the mean of its divisors is an integer number (160237697683).

Almost surely, 2^640200262021 is an apocalyptic number.

It is an amenable number.

640200262021 is a deficient number, since it is larger than the sum of its proper divisors (750528711).

640200262021 is an equidigital number, since it uses as much as digits as its factorization.

640200262021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750528710.

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 640200262021 its reverse (120262002046), we get a palindrome (760462264067).

The spelling of 640200262021 in words is "six hundred forty billion, two hundred million, two hundred sixty-two thousand, twenty-one".