21121012006 has 4 divisors (see below), whose sum is σ = 31681518012. Its totient is φ = 10560506002.

The previous prime is 21121011959. The next prime is 21121012021. The reversal of 21121012006 is 60021012112.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21121012006² (a number of 21 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 as a sum of consecutive naturals, namely, 5280253000 + ... + 5280253003.

It is an arithmetic number, because the mean of its divisors is an integer number (7920379503).

Almost surely, 2^21121012006 is an apocalyptic number.

21121012006 is a deficient number, since it is larger than the sum of its proper divisors (10560506006).

21121012006 is a wasteful number, since it uses less digits than its factorization.

21121012006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10560506005.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21121012006 its reverse (60021012112), we get a palindrome (81142024118).

The spelling of 21121012006 in words is "twenty-one billion, one hundred twenty-one million, twelve thousand, six".