21229897448 has 8 divisors (see below), whose sum is σ = 39806057730. Its totient is φ = 10614948720.

The previous prime is 21229897439. The next prime is 21229897471. The reversal of 21229897448 is 84479892212.

It can be written as a sum of positive squares in only one way, i.e., 19342690084 + 1887207364 = 139078^2 + 43442^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21229897393 and 21229897402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1326868583 + ... + 1326868598.

Almost surely, 2^21229897448 is an apocalyptic number.

It is an amenable number.

21229897448 is a deficient number, since it is larger than the sum of its proper divisors (18576160282).

21229897448 is a wasteful number, since it uses less digits than its factorization.

21229897448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2653737187 (or 2653737183 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 56.

The spelling of 21229897448 in words is "twenty-one billion, two hundred twenty-nine million, eight hundred ninety-seven thousand, four hundred forty-eight".