21213711771378 has 64 divisors (see below), whose sum is σ = 51042699694080. Its totient is φ = 5741810928000.

The previous prime is 21213711771367. The next prime is 21213711771391. The reversal of 21213711771378 is 87317711731212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21213711771378.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18434743 + ... + 19551653.

It is an arithmetic number, because the mean of its divisors is an integer number (797542182720).

Almost surely, 2^{21213711771378} is an apocalyptic number.

21213711771378 is an abundant number, since it is smaller than the sum of its proper divisors (29828987922702).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213711771378 is a wasteful number, since it uses less digits than its factorization.

21213711771378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140743.

The product of its digits is 691488, while the sum is 51.

The spelling of 21213711771378 in words is "twenty-one trillion, two hundred thirteen billion, seven hundred eleven million, seven hundred seventy-one thousand, three hundred seventy-eight".