21647450240 has 64 divisors (see below), whose sum is σ = 55731798360. Its totient is φ = 7992901632.

The previous prime is 21647450197. The next prime is 21647450269. The reversal of 21647450240 is 4205474612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14444193856 + 7203256384 = 120184^2 + 84872^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21647450240² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21647450240.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1292609 + ... + 1309248.

Almost surely, 2^21647450240 is an apocalyptic number.

21647450240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21647450240 is an abundant number, since it is smaller than the sum of its proper divisors (34084348120).

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

21647450240 is a wasteful number, since it uses less digits than its factorization.

21647450240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2601889 (or 2601877 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 35.

The spelling of 21647450240 in words is "twenty-one billion, six hundred forty-seven million, four hundred fifty thousand, two hundred forty".