20635637907 has 18 divisors (see below), whose sum is σ = 27720402564. Its totient is φ = 13654747680.

The previous prime is 20635637873. The next prime is 20635637917. The reversal of 20635637907 is 70973653602.

It is not a de Polignac number, because 20635637907 - 2¹⁶ = 20635572371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20635637917) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 49015557 + ... + 49015977.

Almost surely, 2^20635637907 is an apocalyptic number.

20635637907 is a deficient number, since it is larger than the sum of its proper divisors (7084764657).

20635637907 is an frugal number, since it uses more digits than its factorization.

20635637907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239 (or 621 counting only the distinct ones).

The product of its (nonzero) digits is 1428840, while the sum is 48.

Multiplying 20635637907 by its sum of digits (48), we get a square (990510619536 = 995244²).

The spelling of 20635637907 in words is "twenty billion, six hundred thirty-five million, six hundred thirty-seven thousand, nine hundred seven".