20406137771 has 4 divisors (see below), whose sum is σ = 20445305544. Its totient is φ = 20366970000.

The previous prime is 20406137747. The next prime is 20406137777. The reversal of 20406137771 is 17773160402.

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 20406137771 - 2²² = 20401943467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20406137777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19583105 + ... + 19584146.

It is an arithmetic number, because the mean of its divisors is an integer number (5111326386).

Almost surely, 2^20406137771 is an apocalyptic number.

20406137771 is a deficient number, since it is larger than the sum of its proper divisors (39167773).

20406137771 is an equidigital number, since it uses as much as digits as its factorization.

20406137771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39167772.

The product of its (nonzero) digits is 49392, while the sum is 38.

The spelling of 20406137771 in words is "twenty billion, four hundred six million, one hundred thirty-seven thousand, seven hundred seventy-one".