1020000021221 has 4 divisors (see below), whose sum is σ = 1052903247744. Its totient is φ = 987096794700.

The previous prime is 1020000021169. The next prime is 1020000021247. The reversal of 1020000021221 is 1221200000201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1020000021221 - 2²⁶ = 1019932912357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020000021121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16451613215 + ... + 16451613276.

It is an arithmetic number, because the mean of its divisors is an integer number (263225811936).

Almost surely, 2^{1020000021221} is an apocalyptic number.

It is an amenable number.

1020000021221 is a deficient number, since it is larger than the sum of its proper divisors (32903226523).

1020000021221 is an equidigital number, since it uses as much as digits as its factorization.

1020000021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32903226522.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 1020000021221 its reverse (1221200000201), we get a palindrome (2241200021422).

The spelling of 1020000021221 in words is "one trillion, twenty billion, twenty-one thousand, two hundred twenty-one".