21998381255511 has 8 divisors (see below), whose sum is σ = 29333393925120. Its totient is φ = 14664478044792.

The previous prime is 21998381255483. The next prime is 21998381255519. The reversal of 21998381255511 is 11555218389912.

It is a happy number.

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

It is not a de Polignac number, because 21998381255511 - 2¹⁵ = 21998381222743 is a prime.

It is a super-2 number, since 2×21998381255511² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998381255519) 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, 277318455 + ... + 277397768.

It is an arithmetic number, because the mean of its divisors is an integer number (3666674240640).

Almost surely, 2^{21998381255511} is an apocalyptic number.

21998381255511 is a deficient number, since it is larger than the sum of its proper divisors (7335012669609).

21998381255511 is a wasteful number, since it uses less digits than its factorization.

21998381255511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554729445.

The product of its digits is 7776000, while the sum is 60.

The spelling of 21998381255511 in words is "twenty-one trillion, nine hundred ninety-eight billion, three hundred eighty-one million, two hundred fifty-five thousand, five hundred eleven".