21211020988 has 6 divisors (see below), whose sum is σ = 37119286736. Its totient is φ = 10605510492.

The previous prime is 21211020977. The next prime is 21211021003. The reversal of 21211020988 is 88902011212.

It is a super-2 number, since 2×21211020988² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2651377620 + ... + 2651377627.

Almost surely, 2^21211020988 is an apocalyptic number.

It is an amenable number.

21211020988 is a deficient number, since it is larger than the sum of its proper divisors (15908265748).

21211020988 is a wasteful number, since it uses less digits than its factorization.

21211020988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302755251 (or 5302755249 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 34.

The spelling of 21211020988 in words is "twenty-one billion, two hundred eleven million, twenty thousand, nine hundred eighty-eight".