21368739460 has 12 divisors (see below), whose sum is σ = 44874352908. Its totient is φ = 8547495776.

The previous prime is 21368739449. The next prime is 21368739461. The reversal of 21368739460 is 6493786312.

It can be written as a sum of positive squares in 2 ways, for example, as 16408072836 + 4960666624 = 128094^2 + 70432^2 .

It is a super-2 number, since 2×21368739460² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21368739461) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 534218467 + ... + 534218506.

It is an arithmetic number, because the mean of its divisors is an integer number (3739529409).

Almost surely, 2^21368739460 is an apocalyptic number.

21368739460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21368739460 is an abundant number, since it is smaller than the sum of its proper divisors (23505613448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21368739460 is a wasteful number, since it uses less digits than its factorization.

21368739460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1068436982 (or 1068436980 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 49.

The spelling of 21368739460 in words is "twenty-one billion, three hundred sixty-eight million, seven hundred thirty-nine thousand, four hundred sixty".