21111002116 has 6 divisors (see below), whose sum is σ = 36944253710. Its totient is φ = 10555501056.

The previous prime is 21111002063. The next prime is 21111002117. The reversal of 21111002116 is 61120011112.

It can be written as a sum of positive squares in only one way, i.e., 16911962116 + 4199040000 = 130046^2 + 64800^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21111002116.

It is not an unprimeable number, because it can be changed into a prime (21111002117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2638875261 + ... + 2638875268.

Almost surely, 2^21111002116 is an apocalyptic number.

It is an amenable number.

21111002116 is a deficient number, since it is larger than the sum of its proper divisors (15833251594).

21111002116 is a wasteful number, since it uses less digits than its factorization.

21111002116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5277750533 (or 5277750531 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21111002116 its reverse (61120011112), we get a palindrome (82231013228).

The spelling of 21111002116 in words is "twenty-one billion, one hundred eleven million, two thousand, one hundred sixteen".