20645504337657 has 16 divisors (see below), whose sum is σ = 27548128670720. Its totient is φ = 13753278582912.

The previous prime is 20645504337631. The next prime is 20645504337701. The reversal of 20645504337657 is 75673340554602.

It is not a de Polignac number, because 20645504337657 - 2²² = 20645500143353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20645504337597 and 20645504337606.

It is not an unprimeable number, because it can be changed into a prime (20645504387657) 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, 21377973 + ... + 22322829.

It is an arithmetic number, because the mean of its divisors is an integer number (1721758041920).

Almost surely, 2^{20645504337657} is an apocalyptic number.

It is an amenable number.

20645504337657 is a deficient number, since it is larger than the sum of its proper divisors (6902624333063).

20645504337657 is a wasteful number, since it uses less digits than its factorization.

20645504337657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950352.

The product of its (nonzero) digits is 63504000, while the sum is 57.

The spelling of 20645504337657 in words is "twenty trillion, six hundred forty-five billion, five hundred four million, three hundred thirty-seven thousand, six hundred fifty-seven".