21254542560 has 240 divisors, whose sum is σ = 75514535712. Its totient is φ = 5629824000.

The previous prime is 21254542549. The next prime is 21254542567. The reversal of 21254542560 is 6524545212.

21254542560 is a `hidden beast` number, since 2 + 1 + 2 + 54 + 5 + 42 + 560 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254542567) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1951530 + ... + 1962390.

Almost surely, 2^21254542560 is an apocalyptic number.

21254542560 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 21254542560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37757267856).

21254542560 is an abundant number, since it is smaller than the sum of its proper divisors (54259993152).

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

21254542560 is a wasteful number, since it uses less digits than its factorization.

21254542560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11039 (or 11022 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 36.

The spelling of 21254542560 in words is "twenty-one billion, two hundred fifty-four million, five hundred forty-two thousand, five hundred sixty".