21661016106252 has 48 divisors (see below), whose sum is σ = 50722708700160. Its totient is φ = 7194620701632.

The previous prime is 21661016106193. The next prime is 21661016106277. The reversal of 21661016106252 is 25260161016612.

It is a self number, because there is not a number n which added to its sum of digits gives 21661016106252.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1108203 + ... + 6674589.

It is an arithmetic number, because the mean of its divisors is an integer number (1056723097920).

Almost surely, 2^{21661016106252} is an apocalyptic number.

It is an amenable number.

21661016106252 is an abundant number, since it is smaller than the sum of its proper divisors (29061692593908).

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

21661016106252 is a wasteful number, since it uses less digits than its factorization.

21661016106252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5567550 (or 5567548 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 21661016106252 in words is "twenty-one trillion, six hundred sixty-one billion, sixteen million, one hundred six thousand, two hundred fifty-two".