21211201212120 has 192 divisors, whose sum is σ = 73637431283520. Its totient is φ = 5276483960832.

The previous prime is 21211201212073. The next prime is 21211201212139. The reversal of 21211201212120 is 2121210211212.

21211201212120 is a `hidden beast` number, since 21 + 211 + 201 + 21 + 212 + 0 = 666.

It is a super-2 number, since 2×21211201212120² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21211201212093 and 21211201212102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14644204 + ... + 16027323.

It is an arithmetic number, because the mean of its divisors is an integer number (383528287935).

Almost surely, 2^{21211201212120} is an apocalyptic number.

21211201212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211201212120 is an abundant number, since it is smaller than the sum of its proper divisors (52426230071400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21211201212120 is a wasteful number, since it uses less digits than its factorization.

21211201212120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30671674 (or 30671667 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21211201212120 its reverse (2121210211212), we get a palindrome (23332411423332).

The spelling of 21211201212120 in words is "twenty-one trillion, two hundred eleven billion, two hundred one million, two hundred twelve thousand, one hundred twenty".