21019019201 has 4 divisors (see below), whose sum is σ = 21227128404. Its totient is φ = 20810910000.

The previous prime is 21019019167. The next prime is 21019019209. The reversal of 21019019201 is 10291091012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13959658801 + 7059360400 = 118151^2 + 84020^2 .

It is a cyclic number.

It is not a de Polignac number, because 21019019201 - 2¹⁸ = 21018757057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21019019209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104054450 + ... + 104054651.

It is an arithmetic number, because the mean of its divisors is an integer number (5306782101).

Almost surely, 2^21019019201 is an apocalyptic number.

It is an amenable number.

21019019201 is a deficient number, since it is larger than the sum of its proper divisors (208109203).

21019019201 is a wasteful number, since it uses less digits than its factorization.

21019019201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208109202.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 21019019201 in words is "twenty-one billion, nineteen million, nineteen thousand, two hundred one".