21019017100 has 36 divisors (see below), whose sum is σ = 45624578104. Its totient is φ = 8405153280.

The previous prime is 21019017067. The next prime is 21019017101. The reversal of 21019017100 is 171091012.

It is not an unprimeable number, because it can be changed into a prime (21019017101) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 335452 + ... + 393148.

Almost surely, 2^21019017100 is an apocalyptic number.

21019017100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21019017100 is an abundant number, since it is smaller than the sum of its proper divisors (24605561004).

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

21019017100 is a wasteful number, since it uses less digits than its factorization.

21019017100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61354 (or 61347 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 22.

The spelling of 21019017100 in words is "twenty-one billion, nineteen million, seventeen thousand, one hundred".