21872350081 has 8 divisors (see below), whose sum is σ = 21920561280. Its totient is φ = 21824172048.

The previous prime is 21872350063. The next prime is 21872350117. The reversal of 21872350081 is 18005327812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21872350081 - 2⁷ = 21872349953 is a prime.

It is a super-2 number, since 2×21872350081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21872350081.

It is not an unprimeable number, because it can be changed into a prime (21872354081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1675080 + ... + 1688086.

It is an arithmetic number, because the mean of its divisors is an integer number (2740070160).

Almost surely, 2^21872350081 is an apocalyptic number.

It is an amenable number.

21872350081 is a deficient number, since it is larger than the sum of its proper divisors (48211199).

21872350081 is a wasteful number, since it uses less digits than its factorization.

21872350081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16583.

The product of its (nonzero) digits is 26880, while the sum is 37.

Adding to 21872350081 its reverse (18005327812), we get a palindrome (39877677893).

It can be divided in two parts, 21872 and 350081, that added together give a triangular number (371953 = T₈₆₂).

The spelling of 21872350081 in words is "twenty-one billion, eight hundred seventy-two million, three hundred fifty thousand, eighty-one".