640043425 has 24 divisors (see below), whose sum is σ = 946475136. Its totient is φ = 419802240.

The previous prime is 640043419. The next prime is 640043441. The reversal of 640043425 is 524340046.

It is not a de Polignac number, because 640043425 - 2¹⁷ = 639912353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640043393 and 640043402.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75484 + ... + 83533.

It is an arithmetic number, because the mean of its divisors is an integer number (39436464).

Almost surely, 2^640043425 is an apocalyptic number.

It is an amenable number.

640043425 is a deficient number, since it is larger than the sum of its proper divisors (306431711).

640043425 is a wasteful number, since it uses less digits than its factorization.

640043425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159057 (or 159052 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 640043425 is about 25299.0795287101. The cubic root of 640043425 is about 861.7933664733.

The spelling of 640043425 in words is "six hundred forty million, forty-three thousand, four hundred twenty-five".