21020010019 has 4 divisors (see below), whose sum is σ = 21021016320. Its totient is φ = 21019003720.

The previous prime is 21020010013. The next prime is 21020010041. The reversal of 21020010019 is 91001002012.

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

It is a cyclic number.

It is not a de Polignac number, because 21020010019 - 2¹⁷ = 21019878947 is a prime.

It is a super-2 number, since 2×21020010019² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020009984 and 21020010011.

It is not an unprimeable number, because it can be changed into a prime (21020010013) 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, 471139 + ... + 513820.

It is an arithmetic number, because the mean of its divisors is an integer number (5255254080).

Almost surely, 2^21020010019 is an apocalyptic number.

21020010019 is a deficient number, since it is larger than the sum of its proper divisors (1006301).

21020010019 is an equidigital number, since it uses as much as digits as its factorization.

21020010019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006300.

The product of its (nonzero) digits is 36, while the sum is 16.

The spelling of 21020010019 in words is "twenty-one billion, twenty million, ten thousand, nineteen".