21211001000 has 64 divisors (see below), whose sum is σ = 56724295680. Its totient is φ = 7272340800.

The previous prime is 21211000973. The next prime is 21211001027. The reversal of 21211001000 is 10011212.

It is an interprime number because it is at equal distance from previous prime (21211000973) and next prime (21211001027).

It is a Harshad number since it is a multiple of its sum of digits (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1508072 + ... + 1522071.

It is an arithmetic number, because the mean of its divisors is an integer number (886317120).

Almost surely, 2^21211001000 is an apocalyptic number.

21211001000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211001000 is an abundant number, since it is smaller than the sum of its proper divisors (35513294680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21211001000 is a wasteful number, since it uses less digits than its factorization.

21211001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030171 (or 3030157 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21211001000 its reverse (10011212), we get a palindrome (21221012212).

The spelling of 21211001000 in words is "twenty-one billion, two hundred eleven million, one thousand".