211212000100021 has 4 divisors (see below), whose sum is σ = 211225273037452. Its totient is φ = 211198727162592.

The previous prime is 211212000099917. The next prime is 211212000100091. The reversal of 211212000100021 is 120001000212112.

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 171508201900996 + 39703798199025 = 13096114^2 + 6301095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211212000100021 is a prime.

It is a super-2 number, since 2×211212000100021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211212000099974 and 211212000100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212000100091) 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, 6636444846 + ... + 6636476671.

It is an arithmetic number, because the mean of its divisors is an integer number (52806318259363).

Almost surely, 2^{211212000100021} is an apocalyptic number.

It is an amenable number.

211212000100021 is a deficient number, since it is larger than the sum of its proper divisors (13272937431).

211212000100021 is a wasteful number, since it uses less digits than its factorization.

211212000100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13272937430.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 211212000100021 its reverse (120001000212112), we get a palindrome (331213000312133).

It can be divided in two parts, 2112 and 12000100021, that multiplied together give a palindrome (25344211244352).

The spelling of 211212000100021 in words is "two hundred eleven trillion, two hundred twelve billion, one hundred thousand, twenty-one".