221121212310 has 160 divisors (see below), whose sum is σ = 615496004640. Its totient is φ = 56893197312.

The previous prime is 221121212269. The next prime is 221121212357. The reversal of 221121212310 is 13212121122.

221121212310 is a `hidden beast` number, since 2 + 21 + 121 + 212 + 310 = 666.

It is a super-2 number, since 2×221121212310² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 51746334 + ... + 51750606.

It is an arithmetic number, because the mean of its divisors is an integer number (3846850029).

Almost surely, 2^221121212310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221121212310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307748002320).

221121212310 is an abundant number, since it is smaller than the sum of its proper divisors (394374792330).

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

221121212310 is a wasteful number, since it uses less digits than its factorization.

221121212310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6524 (or 6515 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 221121212310 its reverse (13212121122), we get a palindrome (234333333432).

The spelling of 221121212310 in words is "two hundred twenty-one billion, one hundred twenty-one million, two hundred twelve thousand, three hundred ten".