21015210716510 has 16 divisors (see below), whose sum is σ = 38125232672256. Its totient is φ = 8339894646048.

The previous prime is 21015210716483. The next prime is 21015210716519. The reversal of 21015210716510 is 1561701251012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015210716519) 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, 8273703737 + ... + 8273706276.

It is an arithmetic number, because the mean of its divisors is an integer number (2382827042016).

Almost surely, 2^{21015210716510} is an apocalyptic number.

21015210716510 is a deficient number, since it is larger than the sum of its proper divisors (17110021955746).

21015210716510 is a wasteful number, since it uses less digits than its factorization.

21015210716510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16547410147.

The product of its (nonzero) digits is 4200, while the sum is 32.

Adding to 21015210716510 its reverse (1561701251012), we get a palindrome (22576911967522).

The spelling of 21015210716510 in words is "twenty-one trillion, fifteen billion, two hundred ten million, seven hundred sixteen thousand, five hundred ten".