21909002777 has 4 divisors (see below), whose sum is σ = 21913584336. Its totient is φ = 21904421220.

The previous prime is 21909002749. The next prime is 21909002779. The reversal of 21909002777 is 77720090912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21909002777 - 2²² = 21904808473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21909002779) 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, 2283599 + ... + 2293172.

It is an arithmetic number, because the mean of its divisors is an integer number (5478396084).

Almost surely, 2^21909002777 is an apocalyptic number.

It is an amenable number.

21909002777 is a deficient number, since it is larger than the sum of its proper divisors (4581559).

21909002777 is an equidigital number, since it uses as much as digits as its factorization.

21909002777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4581558.

The product of its (nonzero) digits is 111132, while the sum is 44.

The spelling of 21909002777 in words is "twenty-one billion, nine hundred nine million, two thousand, seven hundred seventy-seven".