640000531 has 2 divisors, whose sum is σ = 640000532. Its totient is φ = 640000530.

The previous prime is 640000523. The next prime is 640000583. The reversal of 640000531 is 135000046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640000531 - 2³ = 640000523 is a prime.

It is a super-2 number, since 2×640000531² = 819201359360563922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 640000499 and 640000508.

It is not a weakly prime, because it can be changed into another prime (640000511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320000265 + 320000266.

It is an arithmetic number, because the mean of its divisors is an integer number (320000266).

Almost surely, 2^640000531 is an apocalyptic number.

640000531 is a deficient number, since it is larger than the sum of its proper divisors (1).

640000531 is an equidigital number, since it uses as much as digits as its factorization.

640000531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 640000531 is about 25298.2317761538. The cubic root of 640000531 is about 861.7741143470.

Adding to 640000531 its reverse (135000046), we get a palindrome (775000577).

The spelling of 640000531 in words is "six hundred forty million, five hundred thirty-one", and thus it is an aban number.