21240212047548 has 144 divisors (see below), whose sum is σ = 53743770372096. Its totient is φ = 6525999567360.

The previous prime is 21240212047543. The next prime is 21240212047559. The reversal of 21240212047548 is 84574021204212.

It is a super-2 number, since 2×21240212047548² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240212047543) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6422802111 + ... + 6422805417.

It is an arithmetic number, because the mean of its divisors is an integer number (373220627584).

Almost surely, 2^{21240212047548} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21240212047548, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26871885186048).

21240212047548 is an abundant number, since it is smaller than the sum of its proper divisors (32503558324548).

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

21240212047548 is a wasteful number, since it uses less digits than its factorization.

21240212047548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6964 (or 6949 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 42.

The spelling of 21240212047548 in words is "twenty-one trillion, two hundred forty billion, two hundred twelve million, forty-seven thousand, five hundred forty-eight".