21021121012 has 12 divisors (see below), whose sum is σ = 36807675940. Its totient is φ = 10504642176.

The previous prime is 21021121007. The next prime is 21021121081. The reversal of 21021121012 is 21012112012.

It can be written as a sum of positive squares in 2 ways, for example, as 8538868836 + 12482252176 = 92406^2 + 111724^2 .

It is a super-2 number, since 2×21021121012² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21021120983 and 21021121001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1471587 + ... + 1485802.

Almost surely, 2^21021121012 is an apocalyptic number.

It is an amenable number.

21021121012 is a deficient number, since it is larger than the sum of its proper divisors (15786554928).

21021121012 is a wasteful number, since it uses less digits than its factorization.

21021121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2959170 (or 2959168 counting only the distinct ones).

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

Adding to 21021121012 its reverse (21012112012), we get a palindrome (42033233024).

The spelling of 21021121012 in words is "twenty-one billion, twenty-one million, one hundred twenty-one thousand, twelve".