640015633 has 2 divisors, whose sum is σ = 640015634. Its totient is φ = 640015632.

The previous prime is 640015619. The next prime is 640015637. The reversal of 640015633 is 336510046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 599858064 + 40157569 = 24492^2 + 6337^2 .

It is a cyclic number.

It is not a de Polignac number, because 640015633 - 2¹⁷ = 639884561 is a prime.

It is not a weakly prime, because it can be changed into another prime (640015637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320007816 + 320007817.

It is an arithmetic number, because the mean of its divisors is an integer number (320007817).

Almost surely, 2^640015633 is an apocalyptic number.

It is an amenable number.

640015633 is a deficient number, since it is larger than the sum of its proper divisors (1).

640015633 is an equidigital number, since it uses as much as digits as its factorization.

640015633 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 28.

The square root of 640015633 is about 25298.5302537519. The cubic root of 640015633 is about 861.7808926801.

Adding to 640015633 its reverse (336510046), we get a palindrome (976525679).

The spelling of 640015633 in words is "six hundred forty million, fifteen thousand, six hundred thirty-three".