21239405591040 has 5760 divisors, whose sum is σ = 104669300736000. Its totient is φ = 4108475105280.

The previous prime is 21239405590957. The next prime is 21239405591077. The reversal of 21239405591040 is 4019550493212.

It is a happy number.

21239405591040 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 9 + 40 + 559 + 10 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (5760).

It is a super-2 number, since 2×21239405591040² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 685142115825 + ... + 685142115855.

It is an arithmetic number, because the mean of its divisors is an integer number (18171753600).

Almost surely, 2^{21239405591040} is an apocalyptic number.

21239405591040 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 21239405591040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52334650368000).

21239405591040 is an abundant number, since it is smaller than the sum of its proper divisors (83429895144960).

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

21239405591040 is an equidigital number, since it uses as much as digits as its factorization.

21239405591040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 21239405591040 in words is "twenty-one trillion, two hundred thirty-nine billion, four hundred five million, five hundred ninety-one thousand, forty".