21135107418 has 16 divisors (see below), whose sum is σ = 43253243616. Its totient is φ = 6881197680.

The previous prime is 21135107393. The next prime is 21135107443. The reversal of 21135107418 is 81470153112.

It is an interprime number because it is at equal distance from previous prime (21135107393) and next prime (21135107443).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40959253 + ... + 40959768.

It is an arithmetic number, because the mean of its divisors is an integer number (2703327726).

Almost surely, 2^21135107418 is an apocalyptic number.

21135107418 is an abundant number, since it is smaller than the sum of its proper divisors (22118136198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21135107418 is a wasteful number, since it uses less digits than its factorization.

21135107418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81919069.

The product of its (nonzero) digits is 6720, while the sum is 33.

The spelling of 21135107418 in words is "twenty-one billion, one hundred thirty-five million, one hundred seven thousand, four hundred eighteen".