21010021220091 has 16 divisors (see below), whose sum is σ = 28122977358080. Its totient is φ = 13951977049440.

The previous prime is 21010021220087. The next prime is 21010021220099. The reversal of 21010021220091 is 19002212001012.

It is not a de Polignac number, because 21010021220091 - 2² = 21010021220087 is a prime.

It is a super-2 number, since 2×21010021220091² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010021220099) 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, 12204865 + ... + 13819506.

It is an arithmetic number, because the mean of its divisors is an integer number (1757686084880).

Almost surely, 2^{21010021220091} is an apocalyptic number.

21010021220091 is a deficient number, since it is larger than the sum of its proper divisors (7112956137989).

21010021220091 is a wasteful number, since it uses less digits than its factorization.

21010021220091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26025426.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 21010021220091 in words is "twenty-one trillion, ten billion, twenty-one million, two hundred twenty thousand, ninety-one".