21213554601256 has 16 divisors (see below), whose sum is σ = 40140326942100. Its totient is φ = 10509467416704.

The previous prime is 21213554601241. The next prime is 21213554601299. The reversal of 21213554601256 is 65210645531212.

It can be written as a sum of positive squares in 2 ways, for example, as 20604427424100 + 609127177156 = 4539210^2 + 780466^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12163734565 + ... + 12163736308.

Almost surely, 2^{21213554601256} is an apocalyptic number.

It is an amenable number.

21213554601256 is a deficient number, since it is larger than the sum of its proper divisors (18926772340844).

21213554601256 is a wasteful number, since it uses less digits than its factorization.

21213554601256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24327470988 (or 24327470984 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 43.

The spelling of 21213554601256 in words is "twenty-one trillion, two hundred thirteen billion, five hundred fifty-four million, six hundred one thousand, two hundred fifty-six".