21908328451 has 16 divisors (see below), whose sum is σ = 23433490080. Its totient is φ = 20409822720.

The previous prime is 21908328439. The next prime is 21908328457. The reversal of 21908328451 is 15482380912.

It is not a de Polignac number, because 21908328451 - 2¹⁵ = 21908295683 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21908328398 and 21908328407.

It is not an unprimeable number, because it can be changed into a prime (21908328457) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2016205 + ... + 2027041.

It is an arithmetic number, because the mean of its divisors is an integer number (1464593130).

Almost surely, 2^21908328451 is an apocalyptic number.

21908328451 is a deficient number, since it is larger than the sum of its proper divisors (1525161629).

21908328451 is a wasteful number, since it uses less digits than its factorization.

21908328451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12054.

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 21908328451 in words is "twenty-one billion, nine hundred eight million, three hundred twenty-eight thousand, four hundred fifty-one".