21210220221278 has 64 divisors (see below), whose sum is σ = 36473823936000. Its totient is φ = 9162075888000.

The previous prime is 21210220221277. The next prime is 21210220221299. The reversal of 21210220221278 is 87212202201212.

It is a super-2 number, since 2×21210220221278² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220221277) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9490913 + ... + 11510771.

It is an arithmetic number, because the mean of its divisors is an integer number (569903499000).

Almost surely, 2^{21210220221278} is an apocalyptic number.

21210220221278 is a deficient number, since it is larger than the sum of its proper divisors (15263603714722).

21210220221278 is a wasteful number, since it uses less digits than its factorization.

21210220221278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2020161.

The product of its (nonzero) digits is 7168, while the sum is 32.

The spelling of 21210220221278 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, two hundred twenty-one thousand, two hundred seventy-eight".