20695897664 has 112 divisors (see below), whose sum is σ = 44930415600. Its totient is φ = 9401204736.

The previous prime is 20695897661. The next prime is 20695897667. The reversal of 20695897664 is 46679859602.

It is an interprime number because it is at equal distance from previous prime (20695897661) and next prime (20695897667).

It can be written as a sum of positive squares in 8 ways, for example, as 7360267264 + 13335630400 = 85792^2 + 115480^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20695897597 and 20695897606.

It is not an unprimeable number, because it can be changed into a prime (20695897661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20510792 + ... + 20511800.

It is an arithmetic number, because the mean of its divisors is an integer number (401164425).

Almost surely, 2^20695897664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20695897664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22465207800).

20695897664 is an abundant number, since it is smaller than the sum of its proper divisors (24234517936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20695897664 is a wasteful number, since it uses less digits than its factorization.

20695897664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400 (or 1390 counting only the distinct ones).

The product of its (nonzero) digits is 39191040, while the sum is 62.

The spelling of 20695897664 in words is "twenty billion, six hundred ninety-five million, eight hundred ninety-seven thousand, six hundred sixty-four".