21216106512401 has 8 divisors (see below), whose sum is σ = 21499841126400. Its totient is φ = 20934055783872.

The previous prime is 21216106512389. The next prime is 21216106512487. The reversal of 21216106512401 is 10421560161212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21216106512401 - 2¹⁸ = 21216106250257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21216106512101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 420946001 + ... + 420996398.

It is an arithmetic number, because the mean of its divisors is an integer number (2687480140800).

Almost surely, 2^{21216106512401} is an apocalyptic number.

It is an amenable number.

21216106512401 is a deficient number, since it is larger than the sum of its proper divisors (283734613999).

21216106512401 is a wasteful number, since it uses less digits than its factorization.

21216106512401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841942735.

The product of its (nonzero) digits is 5760, while the sum is 32.

Adding to 21216106512401 its reverse (10421560161212), we get a palindrome (31637666673613).

The spelling of 21216106512401 in words is "twenty-one trillion, two hundred sixteen billion, one hundred six million, five hundred twelve thousand, four hundred one".