21121202011 has 24 divisors (see below), whose sum is σ = 26518816800. Its totient is φ = 16673836032.

The previous prime is 21121201991. The next prime is 21121202021. The reversal of 21121202011 is 11020212112.

It is not a de Polignac number, because 21121202011 - 2¹¹ = 21121199963 is a prime.

It is a super-2 number, since 2×21121202011² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a junction number, because it is equal to n+sod(n) for n = 21121201982 and 21121202000.

It is not an unprimeable number, because it can be changed into a prime (21121202021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 249090 + ... + 322936.

It is an arithmetic number, because the mean of its divisors is an integer number (1104950700).

Almost surely, 2^21121202011 is an apocalyptic number.

21121202011 is a deficient number, since it is larger than the sum of its proper divisors (5397614789).

21121202011 is a wasteful number, since it uses less digits than its factorization.

21121202011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74323 (or 74316 counting only the distinct ones).

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

Adding to 21121202011 its reverse (11020212112), we get a palindrome (32141414123).

The spelling of 21121202011 in words is "twenty-one billion, one hundred twenty-one million, two hundred two thousand, eleven".