1221312021210 has 48 divisors (see below), whose sum is σ = 3222805468896. Its totient is φ = 320822260704.

The previous prime is 1221312021169. The next prime is 1221312021247. The reversal of 1221312021210 is 121202131221.

1221312021210 is a `hidden beast` number, since 1 + 221 + 31 + 202 + 1 + 210 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 101263624 + ... + 101275683.

It is an arithmetic number, because the mean of its divisors is an integer number (67141780602).

Almost surely, 2^{1221312021210} is an apocalyptic number.

1221312021210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221312021210 is an abundant number, since it is smaller than the sum of its proper divisors (2001493447686).

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

1221312021210 is a wasteful number, since it uses less digits than its factorization.

1221312021210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202539387 (or 202539384 counting only the distinct ones).

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

Adding to 1221312021210 its reverse (121202131221), we get a palindrome (1342514152431).

The spelling of 1221312021210 in words is "one trillion, two hundred twenty-one billion, three hundred twelve million, twenty-one thousand, two hundred ten".