20521642510266 has 32 divisors (see below), whose sum is σ = 41297027091840. Its totient is φ = 6798288763584.

The previous prime is 20521642510207. The next prime is 20521642510267. The reversal of 20521642510266 is 66201524612502.

It is a happy number.

It is a super-2 number, since 2×20521642510266² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521642510267) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1351221 + ... + 6547448.

It is an arithmetic number, because the mean of its divisors is an integer number (1290532096620).

Almost surely, 2^{20521642510266} is an apocalyptic number.

20521642510266 is an abundant number, since it is smaller than the sum of its proper divisors (20775384581574).

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

20521642510266 is a wasteful number, since it uses less digits than its factorization.

20521642510266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7901350.

The product of its (nonzero) digits is 345600, while the sum is 42.

The spelling of 20521642510266 in words is "twenty trillion, five hundred twenty-one billion, six hundred forty-two million, five hundred ten thousand, two hundred sixty-six".