1640664255106 has 4 divisors (see below), whose sum is σ = 2460996382662. Its totient is φ = 820332127552.

The previous prime is 1640664255101. The next prime is 1640664255127. The reversal of 1640664255106 is 6015524660461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1143956454481 + 496707800625 = 1069559^2 + 704775^2 .

It is not an unprimeable number, because it can be changed into a prime (1640664255101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410166063775 + ... + 410166063778.

Almost surely, 2^{1640664255106} is an apocalyptic number.

1640664255106 is a deficient number, since it is larger than the sum of its proper divisors (820332127556).

1640664255106 is an equidigital number, since it uses as much as digits as its factorization.

1640664255106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820332127555.

The product of its (nonzero) digits is 1036800, while the sum is 46.

The spelling of 1640664255106 in words is "one trillion, six hundred forty billion, six hundred sixty-four million, two hundred fifty-five thousand, one hundred six".