21051724519 has 24 divisors (see below), whose sum is σ = 25804967040. Its totient is φ = 17076500784.

The previous prime is 21051724493. The next prime is 21051724583. The reversal of 21051724519 is 91542715012.

It is not a de Polignac number, because 21051724519 - 2¹⁵ = 21051691751 is a prime.

It is a super-2 number, since 2×21051724519² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051728519) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 903672 + ... + 926674.

It is an arithmetic number, because the mean of its divisors is an integer number (1075206960).

Almost surely, 2^21051724519 is an apocalyptic number.

21051724519 is a deficient number, since it is larger than the sum of its proper divisors (4753242521).

21051724519 is a wasteful number, since it uses less digits than its factorization.

21051724519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24019 (or 24012 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 37.

The spelling of 21051724519 in words is "twenty-one billion, fifty-one million, seven hundred twenty-four thousand, five hundred nineteen".