1640694503805 has 128 divisors (see below), whose sum is σ = 3278207877120. Its totient is φ = 684508769280.

The previous prime is 1640694503761. The next prime is 1640694503809. The reversal of 1640694503805 is 5083054960461.

It is not a de Polignac number, because 1640694503805 - 2¹¹ = 1640694501757 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640694503809) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3856879 + ... + 4261091.

It is an arithmetic number, because the mean of its divisors is an integer number (25610999040).

Almost surely, 2^{1640694503805} is an apocalyptic number.

1640694503805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640694503805 is a deficient number, since it is larger than the sum of its proper divisors (1637513373315).

1640694503805 is a wasteful number, since it uses less digits than its factorization.

1640694503805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404331.

The product of its (nonzero) digits is 3110400, while the sum is 51.

The spelling of 1640694503805 in words is "one trillion, six hundred forty billion, six hundred ninety-four million, five hundred three thousand, eight hundred five".