21012021222 has 32 divisors (see below), whose sum is σ = 42383560704. Its totient is φ = 6944162400.

The previous prime is 21012021221. The next prime is 21012021223. The reversal of 21012021222 is 22212021012.

It is an interprime number because it is at equal distance from previous prime (21012021221) and next prime (21012021223).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012021221) 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, 1226697 + ... + 1243707.

It is an arithmetic number, because the mean of its divisors is an integer number (1324486272).

Almost surely, 2^21012021222 is an apocalyptic number.

21012021222 is an abundant number, since it is smaller than the sum of its proper divisors (21371539482).

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

21012021222 is a wasteful number, since it uses less digits than its factorization.

21012021222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18764.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21012021222 its reverse (22212021012), we get a palindrome (43224042234).

The spelling of 21012021222 in words is "twenty-one billion, twelve million, twenty-one thousand, two hundred twenty-two".