21012016605552 has 60 divisors (see below), whose sum is σ = 67205100733680. Its totient is φ = 6003433315584.

The previous prime is 21012016605529. The next prime is 21012016605647. The reversal of 21012016605552 is 25550661021012.

21012016605552 is a `hidden beast` number, since 2 + 10 + 1 + 20 + 16 + 60 + 5 + 552 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10422626277 + ... + 10422628292.

It is an arithmetic number, because the mean of its divisors is an integer number (1120085012228).

Almost surely, 2^{21012016605552} is an apocalyptic number.

It is an amenable number.

21012016605552 is an abundant number, since it is smaller than the sum of its proper divisors (46193084128128).

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

21012016605552 is a wasteful number, since it uses less digits than its factorization.

21012016605552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20845254590 (or 20845254581 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

Adding to 21012016605552 its reverse (25550661021012), we get a palindrome (46562677626564).

The spelling of 21012016605552 in words is "twenty-one trillion, twelve billion, sixteen million, six hundred five thousand, five hundred fifty-two".