1021101221091 has 16 divisors (see below), whose sum is σ = 1556111462400. Its totient is φ = 583431025728.

The previous prime is 1021101221083. The next prime is 1021101221117. The reversal of 1021101221091 is 1901221011201.

It is not a de Polignac number, because 1021101221091 - 2³ = 1021101221083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1021101220091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2080746 + ... + 2524223.

It is an arithmetic number, because the mean of its divisors is an integer number (97256966400).

Almost surely, 2^{1021101221091} is an apocalyptic number.

1021101221091 is a deficient number, since it is larger than the sum of its proper divisors (535010241309).

1021101221091 is a wasteful number, since it uses less digits than its factorization.

1021101221091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4615538.

The product of its (nonzero) digits is 72, while the sum is 21.

Adding to 1021101221091 its reverse (1901221011201), we get a palindrome (2922322232292).

The spelling of 1021101221091 in words is "one trillion, twenty-one billion, one hundred one million, two hundred twenty-one thousand, ninety-one".