21058506678 has 32 divisors (see below), whose sum is σ = 46724584320. Its totient is φ = 6273205760.

The previous prime is 21058506671. The next prime is 21058506701. The reversal of 21058506678 is 87660585012.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21058506671) 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, 2700075 + ... + 2707862.

It is an arithmetic number, because the mean of its divisors is an integer number (1460143260).

Almost surely, 2^21058506678 is an apocalyptic number.

21058506678 is an abundant number, since it is smaller than the sum of its proper divisors (25666077642).

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

21058506678 is a wasteful number, since it uses less digits than its factorization.

21058506678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5408012.

The product of its (nonzero) digits is 806400, while the sum is 48.

The spelling of 21058506678 in words is "twenty-one billion, fifty-eight million, five hundred six thousand, six hundred seventy-eight".