1640115643 has 4 divisors (see below), whose sum is σ = 1650977488. Its totient is φ = 1629253800.

The previous prime is 1640115641. The next prime is 1640115679. The reversal of 1640115643 is 3465110461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3465110461 = 179 ⋅19358159.

It is a cyclic number.

It is not a de Polignac number, because 1640115643 - 2¹ = 1640115641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640115641) 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, 5430696 + ... + 5430997.

It is an arithmetic number, because the mean of its divisors is an integer number (412744372).

Almost surely, 2^1640115643 is an apocalyptic number.

1640115643 is a deficient number, since it is larger than the sum of its proper divisors (10861845).

1640115643 is a wasteful number, since it uses less digits than its factorization.

1640115643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10861844.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1640115643 is about 40498.3412376359. The cubic root of 1640115643 is about 1179.3014257876.

The spelling of 1640115643 in words is "one billion, six hundred forty million, one hundred fifteen thousand, six hundred forty-three".