21406498818091 has 8 divisors (see below), whose sum is σ = 22371111797760. Its totient is φ = 20444710475112.

The previous prime is 21406498818083. The next prime is 21406498818151. The reversal of 21406498818091 is 19081889460412.

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 21406498818091 - 2³ = 21406498818083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21406498818011) 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, 706143675 + ... + 706173988.

It is an arithmetic number, because the mean of its divisors is an integer number (2796388974720).

Almost surely, 2^{21406498818091} is an apocalyptic number.

21406498818091 is a deficient number, since it is larger than the sum of its proper divisors (964612979669).

21406498818091 is a wasteful number, since it uses less digits than its factorization.

21406498818091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412318345.

The product of its (nonzero) digits is 7962624, while the sum is 61.

The spelling of 21406498818091 in words is "twenty-one trillion, four hundred six billion, four hundred ninety-eight million, eight hundred eighteen thousand, ninety-one".