21546245436240 has 320 divisors, whose sum is σ = 78978919311360. Its totient is φ = 4754347100160.

The previous prime is 21546245436203. The next prime is 21546245436257. The reversal of 21546245436240 is 4263454264512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21546245436240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 385201075 + ... + 385257005.

It is an arithmetic number, because the mean of its divisors is an integer number (246809122848).

Almost surely, 2^{21546245436240} is an apocalyptic number.

21546245436240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21546245436240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39489459655680).

21546245436240 is an abundant number, since it is smaller than the sum of its proper divisors (57432673875120).

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

21546245436240 is a wasteful number, since it uses less digits than its factorization.

21546245436240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63890 (or 63884 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 48.

The spelling of 21546245436240 in words is "twenty-one trillion, five hundred forty-six billion, two hundred forty-five million, four hundred thirty-six thousand, two hundred forty".