20640462005 has 16 divisors (see below), whose sum is σ = 25815788544. Its totient is φ = 15824557440.

The previous prime is 20640461977. The next prime is 20640462103. The reversal of 20640462005 is 50026404602.

It is not a de Polignac number, because 20640462005 - 2¹⁸ = 20640199861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 630464 + ... + 662393.

It is an arithmetic number, because the mean of its divisors is an integer number (1613486784).

Almost surely, 2^20640462005 is an apocalyptic number.

It is an amenable number.

20640462005 is a deficient number, since it is larger than the sum of its proper divisors (5175326539).

20640462005 is a wasteful number, since it uses less digits than its factorization.

20640462005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1292996.

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 20640462005 its reverse (50026404602), we get a palindrome (70666866607).

The spelling of 20640462005 in words is "twenty billion, six hundred forty million, four hundred sixty-two thousand, five".