640036511 has 2 divisors, whose sum is σ = 640036512. Its totient is φ = 640036510.

The previous prime is 640036499. The next prime is 640036531. The reversal of 640036511 is 115630046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640036511 - 2¹⁸ = 639774367 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640036531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320018255 + 320018256.

It is an arithmetic number, because the mean of its divisors is an integer number (320018256).

Almost surely, 2^640036511 is an apocalyptic number.

640036511 is a deficient number, since it is larger than the sum of its proper divisors (1).

640036511 is an equidigital number, since it uses as much as digits as its factorization.

640036511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 640036511 is about 25298.9428830534. The cubic root of 640036511 is about 861.7902633188.

Adding to 640036511 its reverse (115630046), we get a palindrome (755666557).

The spelling of 640036511 in words is "six hundred forty million, thirty-six thousand, five hundred eleven".