21501442545040 has 40 divisors (see below), whose sum is σ = 50036843865600. Its totient is φ = 8592664768896.

The previous prime is 21501442545013. The next prime is 21501442545041. The reversal of 21501442545040 is 4054524410512.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21501442545041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123541390 + ... + 123715309.

It is an arithmetic number, because the mean of its divisors is an integer number (1250921096640).

Almost surely, 2^{21501442545040} is an apocalyptic number.

21501442545040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21501442545040 is an abundant number, since it is smaller than the sum of its proper divisors (28535401320560).

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

21501442545040 is a wasteful number, since it uses less digits than its factorization.

21501442545040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247257799 (or 247257793 counting only the distinct ones).

The product of its (nonzero) digits is 128000, while the sum is 37.

Adding to 21501442545040 its reverse (4054524410512), we get a palindrome (25555966955552).

The spelling of 21501442545040 in words is "twenty-one trillion, five hundred one billion, four hundred forty-two million, five hundred forty-five thousand, forty".