21218061548 has 6 divisors (see below), whose sum is σ = 37131607716. Its totient is φ = 10609030772.

The previous prime is 21218061493. The next prime is 21218061581. The reversal of 21218061548 is 84516081212.

It is a super-2 number, since 2×21218061548² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2652257690 + ... + 2652257697.

It is an arithmetic number, because the mean of its divisors is an integer number (6188601286).

Almost surely, 2^21218061548 is an apocalyptic number.

It is an amenable number.

21218061548 is a deficient number, since it is larger than the sum of its proper divisors (15913546168).

21218061548 is a wasteful number, since it uses less digits than its factorization.

21218061548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5304515391 (or 5304515389 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 38.

The spelling of 21218061548 in words is "twenty-one billion, two hundred eighteen million, sixty-one thousand, five hundred forty-eight".