640293228450 has 162 divisors, whose sum is σ = 1749420438129. Its totient is φ = 167897679840.

The previous prime is 640293228427. The next prime is 640293228479. The reversal of 640293228450 is 54822392046.

It can be written as a sum of positive squares in 2 ways, for example, as 627487363881 + 12805864569 = 792141^2 + 113163^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=565815.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 640293228396 and 640293228405.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1137287869 + ... + 1137288431.

Almost surely, 2^640293228450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640293228450

640293228450 is an abundant number, since it is smaller than the sum of its proper divisors (1109127209679).

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

640293228450 is an equidigital number, since it uses as much as digits as its factorization.

640293228450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1278 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 640293228450 in words is "six hundred forty billion, two hundred ninety-three million, two hundred twenty-eight thousand, four hundred fifty".