1640540233 has 2 divisors, whose sum is σ = 1640540234. Its totient is φ = 1640540232.

The previous prime is 1640540221. The next prime is 1640540249. The reversal of 1640540233 is 3320450461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 850480569 + 790059664 = 29163^2 + 28108^2 .

It is an emirp because it is prime and its reverse (3320450461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1640540233 - 2⁵ = 1640540201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640540263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820270116 + 820270117.

It is an arithmetic number, because the mean of its divisors is an integer number (820270117).

Almost surely, 2^1640540233 is an apocalyptic number.

It is an amenable number.

1640540233 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640540233 is an equidigital number, since it uses as much as digits as its factorization.

1640540233 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 1640540233 is about 40503.5829649674. The cubic root of 1640540233 is about 1179.4031821063.

Adding to 1640540233 its reverse (3320450461), we get a palindrome (4960990694).

The spelling of 1640540233 in words is "one billion, six hundred forty million, five hundred forty thousand, two hundred thirty-three".