21401212620406 has 4 divisors (see below), whose sum is σ = 32101818930612. Its totient is φ = 10700606310202.

The previous prime is 21401212620377. The next prime is 21401212620427. The reversal of 21401212620406 is 60402621210412.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5350303155100 + ... + 5350303155103.

It is an arithmetic number, because the mean of its divisors is an integer number (8025454732653).

Almost surely, 2^{21401212620406} is an apocalyptic number.

21401212620406 is a deficient number, since it is larger than the sum of its proper divisors (10700606310206).

21401212620406 is a wasteful number, since it uses less digits than its factorization.

21401212620406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10700606310205.

The product of its (nonzero) digits is 9216, while the sum is 31.

Adding to 21401212620406 its reverse (60402621210412), we get a palindrome (81803833830818).

The spelling of 21401212620406 in words is "twenty-one trillion, four hundred one billion, two hundred twelve million, six hundred twenty thousand, four hundred six".