21445749648 has 80 divisors (see below), whose sum is σ = 61599053440. Its totient is φ = 7143728256.

The previous prime is 21445749643. The next prime is 21445749649. The reversal of 21445749648 is 84694754412.

21445749648 is a `hidden beast` number, since 2 + 1 + 4 + 4 + 574 + 9 + 64 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 21445749594 and 21445749603.

It is not an unprimeable number, because it can be changed into a prime (21445749643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 650490 + ... + 682662.

It is an arithmetic number, because the mean of its divisors is an integer number (769988168).

Almost surely, 2^21445749648 is an apocalyptic number.

It is an amenable number.

21445749648 is an abundant number, since it is smaller than the sum of its proper divisors (40153303792).

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

21445749648 is a wasteful number, since it uses less digits than its factorization.

21445749648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33733 (or 33721 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 54.

The spelling of 21445749648 in words is "twenty-one billion, four hundred forty-five million, seven hundred forty-nine thousand, six hundred forty-eight".