21449491056 has 120 divisors (see below), whose sum is σ = 72639931104. Its totient is φ = 5767925760.

The previous prime is 21449491027. The next prime is 21449491057. The reversal of 21449491056 is 65019494412.

21449491056 is a `hidden beast` number, since 21 + 4 + 494 + 91 + 0 + 56 = 666.

It is a super-2 number, since 2×21449491056² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21449491057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 608725 + ... + 642996.

Almost surely, 2^21449491056 is an apocalyptic number.

It is an amenable number.

21449491056 is an abundant number, since it is smaller than the sum of its proper divisors (51190440048).

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

21449491056 is a wasteful number, since it uses less digits than its factorization.

21449491056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1251759 (or 1251750 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 21449491056 in words is "twenty-one billion, four hundred forty-nine million, four hundred ninety-one thousand, fifty-six".