1221220110021 has 8 divisors (see below), whose sum is σ = 1630301243424. Its totient is φ = 813142858320.

The previous prime is 1221220110017. The next prime is 1221220110023. The reversal of 1221220110021 is 1200110221221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221220110021 - 2² = 1221220110017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220110023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250967586 + ... + 250972451.

It is an arithmetic number, because the mean of its divisors is an integer number (203787655428).

Almost surely, 2^{1221220110021} is an apocalyptic number.

It is an amenable number.

1221220110021 is a deficient number, since it is larger than the sum of its proper divisors (409081133403).

1221220110021 is an equidigital number, since it uses as much as digits as its factorization.

1221220110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501940851.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221220110021 its reverse (1200110221221), we get a palindrome (2421330331242).

The spelling of 1221220110021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred ten thousand, twenty-one".