21247119556 has 12 divisors (see below), whose sum is σ = 40042648492. Its totient is φ = 9806362848.

The previous prime is 21247119521. The next prime is 21247119559. The reversal of 21247119556 is 65591174212.

It can be written as a sum of positive squares in 2 ways, for example, as 1340731456 + 19906388100 = 36616^2 + 141090^2 .

It is not an unprimeable number, because it can be changed into a prime (21247119559) 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, 204299175 + ... + 204299278.

Almost surely, 2^21247119556 is an apocalyptic number.

21247119556 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21247119556 is a deficient number, since it is larger than the sum of its proper divisors (18795528936).

21247119556 is a wasteful number, since it uses less digits than its factorization.

21247119556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408598470 (or 408598468 counting only the distinct ones).

The product of its digits is 151200, while the sum is 43.

The spelling of 21247119556 in words is "twenty-one billion, two hundred forty-seven million, one hundred nineteen thousand, five hundred fifty-six".