1640404505 has 8 divisors (see below), whose sum is σ = 2054071872. Its totient is φ = 1255265968.

The previous prime is 1640404457. The next prime is 1640404531. The reversal of 1640404505 is 5054040461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1640404505 - 2¹⁴ = 1640388121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7132079 + ... + 7132308.

It is an arithmetic number, because the mean of its divisors is an integer number (256758984).

Almost surely, 2^1640404505 is an apocalyptic number.

It is an amenable number.

1640404505 is a deficient number, since it is larger than the sum of its proper divisors (413667367).

1640404505 is a wasteful number, since it uses less digits than its factorization.

1640404505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14264415.

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 1640404505 is about 40501.9074242189. The cubic root of 1640404505 is about 1179.3706557375.

Adding to 1640404505 its reverse (5054040461), we get a palindrome (6694444966).

The spelling of 1640404505 in words is "one billion, six hundred forty million, four hundred four thousand, five hundred five".