21098004481 has 4 divisors (see below), whose sum is σ = 21588655792. Its totient is φ = 20607353172.

The previous prime is 21098004461. The next prime is 21098004493. The reversal of 21098004481 is 18440089012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21098004481 - 2¹¹ = 21098002433 is a prime.

It is a super-2 number, since 2×21098004481² (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 21098004481.

It is not an unprimeable number, because it can be changed into a prime (21098004451) 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, 245325591 + ... + 245325676.

It is an arithmetic number, because the mean of its divisors is an integer number (5397163948).

Almost surely, 2^21098004481 is an apocalyptic number.

It is an amenable number.

21098004481 is a deficient number, since it is larger than the sum of its proper divisors (490651311).

21098004481 is an equidigital number, since it uses as much as digits as its factorization.

21098004481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490651310.

The product of its (nonzero) digits is 18432, while the sum is 37.

The spelling of 21098004481 in words is "twenty-one billion, ninety-eight million, four thousand, four hundred eighty-one".