1221022010021 has 4 divisors (see below), whose sum is σ = 1332024010944. Its totient is φ = 1110020009100.

The previous prime is 1221022010011. The next prime is 1221022010053. The reversal of 1221022010021 is 1200102201221.

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 a de Polignac number, because none of the positive numbers 2^k-1221022010021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221022009978 and 1221022010005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221022010011) 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, 55501000445 + ... + 55501000466.

It is an arithmetic number, because the mean of its divisors is an integer number (333006002736).

Almost surely, 2^{1221022010021} is an apocalyptic number.

1221022010021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221022010021 is a deficient number, since it is larger than the sum of its proper divisors (111002000923).

1221022010021 is a wasteful number, since it uses less digits than its factorization.

1221022010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111002000922.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1221022010021 its reverse (1200102201221), we get a palindrome (2421124211242).

The spelling of 1221022010021 in words is "one trillion, two hundred twenty-one billion, twenty-two million, ten thousand, twenty-one".