20971552639 has 8 divisors (see below), whose sum is σ = 21277389312. Its totient is φ = 20666217600.

The previous prime is 20971552619. The next prime is 20971552663. The reversal of 20971552639 is 93625517902.

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 20971552639 - 2²¹ = 20969455487 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20971552592 and 20971552601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20971552619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40774 + ... + 208819.

It is an arithmetic number, because the mean of its divisors is an integer number (2659673664).

Almost surely, 2^20971552639 is an apocalyptic number.

20971552639 is a deficient number, since it is larger than the sum of its proper divisors (305836673).

20971552639 is a wasteful number, since it uses less digits than its factorization.

20971552639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250817.

The product of its (nonzero) digits is 1020600, while the sum is 49.

The spelling of 20971552639 in words is "twenty billion, nine hundred seventy-one million, five hundred fifty-two thousand, six hundred thirty-nine".