211020010021 has 4 divisors (see below), whose sum is σ = 212887443852. Its totient is φ = 209152576192.

The previous prime is 211020009973. The next prime is 211020010027. The reversal of 211020010021 is 120010020112.

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 41514062500 + 169505947521 = 203750^2 + 411711^2 .

It is a cyclic number.

It is not a de Polignac number, because 211020010021 - 2²³ = 211011621413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211020010027) 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, 933716746 + ... + 933716971.

It is an arithmetic number, because the mean of its divisors is an integer number (53221860963).

Almost surely, 2^211020010021 is an apocalyptic number.

It is an amenable number.

211020010021 is a deficient number, since it is larger than the sum of its proper divisors (1867433831).

211020010021 is a wasteful number, since it uses less digits than its factorization.

211020010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1867433830.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 211020010021 its reverse (120010020112), we get a palindrome (331030030133).

The spelling of 211020010021 in words is "two hundred eleven billion, twenty million, ten thousand, twenty-one".