21001112121019 has 4 divisors (see below), whose sum is σ = 21004152682744. Its totient is φ = 20998071559296.

The previous prime is 21001112120951. The next prime is 21001112121023. The reversal of 21001112121019 is 91012121110012.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001112121019 is a prime.

It is a super-2 number, since 2×21001112121019² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001112121089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1520270502 + ... + 1520284315.

It is an arithmetic number, because the mean of its divisors is an integer number (5251038170686).

Almost surely, 2^{21001112121019} is an apocalyptic number.

21001112121019 is a deficient number, since it is larger than the sum of its proper divisors (3040561725).

21001112121019 is an equidigital number, since it uses as much as digits as its factorization.

21001112121019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3040561724.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 21001112121019 in words is "twenty-one trillion, one billion, one hundred twelve million, one hundred twenty-one thousand, nineteen".