21210421401 has 16 divisors (see below), whose sum is σ = 33839989120. Its totient is φ = 13052566800.

The previous prime is 21210421381. The next prime is 21210421429. The reversal of 21210421401 is 10412401212.

21210421401 is a `hidden beast` number, since 212 + 10 + 42 + 1 + 401 = 666.

It is not a de Polignac number, because 21210421401 - 2¹⁰ = 21210420377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210420401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30213925 + ... + 30214626.

It is an arithmetic number, because the mean of its divisors is an integer number (2114999320).

Almost surely, 2^21210421401 is an apocalyptic number.

It is an amenable number.

21210421401 is a deficient number, since it is larger than the sum of its proper divisors (12629567719).

21210421401 is a wasteful number, since it uses less digits than its factorization.

21210421401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60428573 (or 60428567 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21210421401 its reverse (10412401212), we get a palindrome (31622822613).

The spelling of 21210421401 in words is "twenty-one billion, two hundred ten million, four hundred twenty-one thousand, four hundred one".