21727377759 has 4 divisors (see below), whose sum is σ = 28969837016. Its totient is φ = 14484918504.

The previous prime is 21727377647. The next prime is 21727377803. The reversal of 21727377759 is 95777372712.

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

It is not a de Polignac number, because 21727377759 - 2¹⁶ = 21727312223 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21727377699 and 21727377708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21727377359) 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, 3621229624 + ... + 3621229629.

It is an arithmetic number, because the mean of its divisors is an integer number (7242459254).

Almost surely, 2^21727377759 is an apocalyptic number.

21727377759 is a deficient number, since it is larger than the sum of its proper divisors (7242459257).

21727377759 is an equidigital number, since it uses as much as digits as its factorization.

21727377759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7242459256.

The product of its digits is 9075780, while the sum is 57.

The spelling of 21727377759 in words is "twenty-one billion, seven hundred twenty-seven million, three hundred seventy-seven thousand, seven hundred fifty-nine".