20011631779 has 4 divisors (see below), whose sum is σ = 20657168320. Its totient is φ = 19366095240.

The previous prime is 20011631777. The next prime is 20011631789. The reversal of 20011631779 is 97713611002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20011631779 - 2¹ = 20011631777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20011631777) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 322768224 + ... + 322768285.

It is an arithmetic number, because the mean of its divisors is an integer number (5164292080).

Almost surely, 2^20011631779 is an apocalyptic number.

20011631779 is a deficient number, since it is larger than the sum of its proper divisors (645536541).

20011631779 is an equidigital number, since it uses as much as digits as its factorization.

20011631779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645536540.

The product of its (nonzero) digits is 15876, while the sum is 37.

The spelling of 20011631779 in words is "twenty billion, eleven million, six hundred thirty-one thousand, seven hundred seventy-nine".