1221000021210 has 32 divisors (see below), whose sum is σ = 2933009570880. Its totient is φ = 325310059008.

The previous prime is 1221000021181. The next prime is 1221000021239. The reversal of 1221000021210 is 121200001221.

It is an interprime number because it is at equal distance from previous prime (1221000021181) and next prime (1221000021239).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18087415 + ... + 18154794.

It is an arithmetic number, because the mean of its divisors is an integer number (91656549090).

Almost surely, 2^{1221000021210} is an apocalyptic number.

1221000021210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221000021210 is an abundant number, since it is smaller than the sum of its proper divisors (1712009549670).

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

1221000021210 is a wasteful number, since it uses less digits than its factorization.

1221000021210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36243342.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221000021210 its reverse (121200001221), we get a palindrome (1342200022431).

The spelling of 1221000021210 in words is "one trillion, two hundred twenty-one billion, twenty-one thousand, two hundred ten".