20634465665 has 16 divisors (see below), whose sum is σ = 27024757056. Its totient is φ = 15000014400.

The previous prime is 20634465661. The next prime is 20634465679. The reversal of 20634465665 is 56656443602.

It is a happy number.

It is not a de Polignac number, because 20634465665 - 2² = 20634465661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20634465661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36950 + ... + 206480.

It is an arithmetic number, because the mean of its divisors is an integer number (1689047316).

Almost surely, 2^20634465665 is an apocalyptic number.

It is an amenable number.

20634465665 is a deficient number, since it is larger than the sum of its proper divisors (6390291391).

20634465665 is a wasteful number, since it uses less digits than its factorization.

20634465665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171760.

The product of its (nonzero) digits is 3110400, while the sum is 47.

The spelling of 20634465665 in words is "twenty billion, six hundred thirty-four million, four hundred sixty-five thousand, six hundred sixty-five".