21391058439680 has 160 divisors (see below), whose sum is σ = 51709510093824. Its totient is φ = 8486387490816.

The previous prime is 21391058439629. The next prime is 21391058439689. The reversal of 21391058439680 is 8693485019312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21391058439689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203162729 + ... + 203267991.

Almost surely, 2^{21391058439680} is an apocalyptic number.

21391058439680 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 21391058439680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25854755046912).

21391058439680 is an abundant number, since it is smaller than the sum of its proper divisors (30318451654144).

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

21391058439680 is a wasteful number, since it uses less digits than its factorization.

21391058439680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105936 (or 105920 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 59.

The spelling of 21391058439680 in words is "twenty-one trillion, three hundred ninety-one billion, fifty-eight million, four hundred thirty-nine thousand, six hundred eighty".