21105458439 has 32 divisors (see below), whose sum is σ = 31109320704. Its totient is φ = 12644709120.

The previous prime is 21105458377. The next prime is 21105458443. The reversal of 21105458439 is 93485450112.

It is not a de Polignac number, because 21105458439 - 2¹¹ = 21105456391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21105458439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105458939) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 765162 + ... + 792264.

It is an arithmetic number, because the mean of its divisors is an integer number (972166272).

Almost surely, 2^21105458439 is an apocalyptic number.

21105458439 is a deficient number, since it is larger than the sum of its proper divisors (10003862265).

21105458439 is a wasteful number, since it uses less digits than its factorization.

21105458439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27647.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 21105458439 in words is "twenty-one billion, one hundred five million, four hundred fifty-eight thousand, four hundred thirty-nine".