21901884019 has 4 divisors (see below), whose sum is σ = 22260931360. Its totient is φ = 21542836680.

The previous prime is 21901883999. The next prime is 21901884031. The reversal of 21901884019 is 91048810912.

It is a happy number.

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 21901884019 - 2³¹ = 19754400371 is a prime.

It is a super-2 number, since 2×21901884019² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21901884119) 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, 179523579 + ... + 179523700.

It is an arithmetic number, because the mean of its divisors is an integer number (5565232840).

Almost surely, 2^21901884019 is an apocalyptic number.

21901884019 is a deficient number, since it is larger than the sum of its proper divisors (359047341).

21901884019 is an equidigital number, since it uses as much as digits as its factorization.

21901884019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359047340.

The product of its (nonzero) digits is 41472, while the sum is 43.

The spelling of 21901884019 in words is "twenty-one billion, nine hundred one million, eight hundred eighty-four thousand, nineteen".