21001011000 has 64 divisors (see below), whose sum is σ = 65523163680. Its totient is φ = 5600268800.

The previous prime is 21001010983. The next prime is 21001011043. The reversal of 21001011000 is 11010012.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21001011000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3497169 + ... + 3503168.

Almost surely, 2^21001011000 is an apocalyptic number.

21001011000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001011000 is an abundant number, since it is smaller than the sum of its proper divisors (44522152680).

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

21001011000 is a wasteful number, since it uses less digits than its factorization.

21001011000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000361 (or 7000347 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 6.

Adding to 21001011000 its reverse (11010012), we get a palindrome (21012021012).

The spelling of 21001011000 in words is "twenty-one billion, one million, eleven thousand".