21268780449 has 8 divisors (see below), whose sum is σ = 32409570240. Its totient is φ = 12153588816.

The previous prime is 21268780447. The next prime is 21268780453. The reversal of 21268780449 is 94408786212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21268780449 - 2¹ = 21268780447 is a prime.

It is a super-2 number, since 2×21268780449² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21268780447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 506399514 + ... + 506399555.

It is an arithmetic number, because the mean of its divisors is an integer number (4051196280).

Almost surely, 2^21268780449 is an apocalyptic number.

It is an amenable number.

21268780449 is a deficient number, since it is larger than the sum of its proper divisors (11140789791).

21268780449 is a wasteful number, since it uses less digits than its factorization.

21268780449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012799079.

The product of its (nonzero) digits is 1548288, while the sum is 51.

The spelling of 21268780449 in words is "twenty-one billion, two hundred sixty-eight million, seven hundred eighty thousand, four hundred forty-nine".