1220100220021 has 4 divisors (see below), whose sum is σ = 1220102559532. Its totient is φ = 1220097880512.

The previous prime is 1220100220013. The next prime is 1220100220037. The reversal of 1220100220021 is 1200220010221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 768052420996 + 452047799025 = 876386^2 + 672345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220100220021 - 2³ = 1220100220013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220100219983 and 1220100220010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220100220061) 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, 7375 + ... + 1562131.

It is an arithmetic number, because the mean of its divisors is an integer number (305025639883).

Almost surely, 2^{1220100220021} is an apocalyptic number.

It is an amenable number.

1220100220021 is a deficient number, since it is larger than the sum of its proper divisors (2339511).

1220100220021 is an equidigital number, since it uses as much as digits as its factorization.

1220100220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2339510.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 1220100220021 its reverse (1200220010221), we get a palindrome (2420320230242).

The spelling of 1220100220021 in words is "one trillion, two hundred twenty billion, one hundred million, two hundred twenty thousand, twenty-one".