21648587049 has 12 divisors (see below), whose sum is σ = 33109603956. Its totient is φ = 13583427072.

The previous prime is 21648587047. The next prime is 21648587057. The reversal of 21648587049 is 94078584612.

It is a happy number.

21648587049 is a `hidden beast` number, since 2 + 16 + 4 + 8 + 587 + 0 + 49 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5964781824 + 15683805225 = 77232^2 + 125235^2 .

It is not a de Polignac number, because 21648587049 - 2¹ = 21648587047 is a prime.

It is a super-2 number, since 2×21648587049² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21648586986 and 21648587004.

It is not an unprimeable number, because it can be changed into a prime (21648587047) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70746864 + ... + 70747169.

It is an arithmetic number, because the mean of its divisors is an integer number (2759133663).

Almost surely, 2^21648587049 is an apocalyptic number.

It is an amenable number.

21648587049 is a deficient number, since it is larger than the sum of its proper divisors (11461016907).

21648587049 is a wasteful number, since it uses less digits than its factorization.

21648587049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141494056 (or 141494053 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 21648587049 in words is "twenty-one billion, six hundred forty-eight million, five hundred eighty-seven thousand, forty-nine".