21515820230 has 16 divisors (see below), whose sum is σ = 38740418640. Its totient is φ = 8603674272.

The previous prime is 21515820217. The next prime is 21515820233. The reversal of 21515820230 is 3202851512.

It is a junction number, because it is equal to n+sod(n) for n = 21515820193 and 21515820202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515820233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 297509 + ... + 362688.

It is an arithmetic number, because the mean of its divisors is an integer number (2421276165).

Almost surely, 2^21515820230 is an apocalyptic number.

21515820230 is a deficient number, since it is larger than the sum of its proper divisors (17224598410).

21515820230 is a wasteful number, since it uses less digits than its factorization.

21515820230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663463.

The product of its (nonzero) digits is 4800, while the sum is 29.

The spelling of 21515820230 in words is "twenty-one billion, five hundred fifteen million, eight hundred twenty thousand, two hundred thirty".