21111021007 has 8 divisors (see below), whose sum is σ = 21334154400. Its totient is φ = 20888237280.

The previous prime is 21111020977. The next prime is 21111021013. The reversal of 21111021007 is 70012011112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21111021007 - 2²⁷ = 20976803279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111081007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34869 + ... + 208417.

It is an arithmetic number, because the mean of its divisors is an integer number (2666769300).

Almost surely, 2^21111021007 is an apocalyptic number.

21111021007 is a deficient number, since it is larger than the sum of its proper divisors (223133393).

21111021007 is a wasteful number, since it uses less digits than its factorization.

21111021007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174833.

The product of its (nonzero) digits is 28, while the sum is 16.

Adding to 21111021007 its reverse (70012011112), we get a palindrome (91123032119).

The spelling of 21111021007 in words is "twenty-one billion, one hundred eleven million, twenty-one thousand, seven".