1640947853 has 4 divisors (see below), whose sum is σ = 1665439680. Its totient is φ = 1616456028.

The previous prime is 1640947837. The next prime is 1640947859. The reversal of 1640947853 is 3587490461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1640947853 - 2⁴ = 1640947837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1640947798 and 1640947807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640947859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12245813 + ... + 12245946.

It is an arithmetic number, because the mean of its divisors is an integer number (416359920).

Almost surely, 2^1640947853 is an apocalyptic number.

It is an amenable number.

1640947853 is a deficient number, since it is larger than the sum of its proper divisors (24491827).

1640947853 is an equidigital number, since it uses as much as digits as its factorization.

1640947853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24491826.

The product of its (nonzero) digits is 725760, while the sum is 47.

The square root of 1640947853 is about 40508.6145529565. The cubic root of 1640947853 is about 1179.5008549143.

The spelling of 1640947853 in words is "one billion, six hundred forty million, nine hundred forty-seven thousand, eight hundred fifty-three".