21115655254610 has 48 divisors (see below), whose sum is σ = 44651354998680. Its totient is φ = 7167973478400.

The previous prime is 21115655254607. The next prime is 21115655254633. The reversal of 21115655254610 is 1645255651112.

It can be written as a sum of positive squares in 4 ways, for example, as 20900376886249 + 215278368361 = 4571693^2 + 463981^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 213283055 + ... + 213382034.

Almost surely, 2^{21115655254610} is an apocalyptic number.

21115655254610 is an abundant number, since it is smaller than the sum of its proper divisors (23535699744070).

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

21115655254610 is a wasteful number, since it uses less digits than its factorization.

21115655254610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426665211 (or 426665204 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 44.

The spelling of 21115655254610 in words is "twenty-one trillion, one hundred fifteen billion, six hundred fifty-five million, two hundred fifty-four thousand, six hundred ten".