21101212121012 has 36 divisors (see below), whose sum is σ = 37907252160960. Its totient is φ = 10274848369104.

The previous prime is 21101212121009. The next prime is 21101212121051. The reversal of 21101212121012 is 21012121210112.

It is a super-2 number, since 2×21101212121012² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1202828 + ... + 6606755.

Almost surely, 2^{21101212121012} is an apocalyptic number.

It is an amenable number.

21101212121012 is a deficient number, since it is larger than the sum of its proper divisors (16806040039948).

21101212121012 is a wasteful number, since it uses less digits than its factorization.

21101212121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7809860 (or 7809751 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21101212121012 its reverse (21012121210112), we get a palindrome (42113333331124).

The spelling of 21101212121012 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, one hundred twenty-one thousand, twelve".