20100021000 has 64 divisors (see below), whose sum is σ = 62712074880. Its totient is φ = 5360004800.

The previous prime is 20100020999. The next prime is 20100021013. The reversal of 20100021000 is 12000102.

It is a happy number.

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 20100021000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3347004 + ... + 3353003.

It is an arithmetic number, because the mean of its divisors is an integer number (979876170).

Almost surely, 2^20100021000 is an apocalyptic number.

20100021000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20100021000 is an abundant number, since it is smaller than the sum of its proper divisors (42612053880).

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

20100021000 is a wasteful number, since it uses less digits than its factorization.

20100021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6700031 (or 6700017 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

Adding to 20100021000 its reverse (12000102), we get a palindrome (20112021102).

The spelling of 20100021000 in words is "twenty billion, one hundred million, twenty-one thousand".