21213713503878 has 64 divisors (see below), whose sum is σ = 48758308784640. Its totient is φ = 6027336057600.

The previous prime is 21213713503867. The next prime is 21213713503901. The reversal of 21213713503878 is 87830531731212.

It is a self number, because there is not a number n which added to its sum of digits gives 21213713503878.

It is a congruent number.

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, 298031233 + ... + 298102403.

It is an arithmetic number, because the mean of its divisors is an integer number (761848574760).

Almost surely, 2^{21213713503878} is an apocalyptic number.

21213713503878 is an abundant number, since it is smaller than the sum of its proper divisors (27544595280762).

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

21213713503878 is a wasteful number, since it uses less digits than its factorization.

21213713503878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110573.

The product of its (nonzero) digits is 1693440, while the sum is 51.

The spelling of 21213713503878 in words is "twenty-one trillion, two hundred thirteen billion, seven hundred thirteen million, five hundred three thousand, eight hundred seventy-eight".