21213212677777 has 8 divisors (see below), whose sum is σ = 21669246133632. Its totient is φ = 20757374576400.

The previous prime is 21213212677661. The next prime is 21213212677781. The reversal of 21213212677777 is 77777621231212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21213212677777 - 2¹⁹ = 21213212153489 is a prime.

It is a super-2 number, since 2×21213212677777² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213212677277) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48619099 + ... + 49053472.

It is an arithmetic number, because the mean of its divisors is an integer number (2708655766704).

Almost surely, 2^{21213212677777} is an apocalyptic number.

It is an amenable number.

21213212677777 is a deficient number, since it is larger than the sum of its proper divisors (456033455855).

21213212677777 is an equidigital number, since it uses as much as digits as its factorization.

21213212677777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97677239.

The product of its digits is 4840416, while the sum is 55.

The spelling of 21213212677777 in words is "twenty-one trillion, two hundred thirteen billion, two hundred twelve million, six hundred seventy-seven thousand, seven hundred seventy-seven".