21006506738770 has 64 divisors (see below), whose sum is σ = 45553604889600. Its totient is φ = 6813291464640.

The previous prime is 21006506738761. The next prime is 21006506738839. The reversal of 21006506738770 is 7783760560012.

It is a super-2 number, since 2×21006506738770² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10509600 + ... + 12347659.

It is an arithmetic number, because the mean of its divisors is an integer number (711775076400).

Almost surely, 2^{21006506738770} is an apocalyptic number.

21006506738770 is an abundant number, since it is smaller than the sum of its proper divisors (24547098150830).

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

21006506738770 is a wasteful number, since it uses less digits than its factorization.

21006506738770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22857983.

The product of its (nonzero) digits is 2963520, while the sum is 52.

The spelling of 21006506738770 in words is "twenty-one trillion, six billion, five hundred six million, seven hundred thirty-eight thousand, seven hundred seventy".