21001550101 has 4 divisors (see below), whose sum is σ = 24001771552. Its totient is φ = 18001328652.

The previous prime is 21001550099. The next prime is 21001550111. The reversal of 21001550101 is 10105510012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21001550101 - 2¹ = 21001550099 is a prime.

It is a super-2 number, since 2×21001550101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001550111) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1500110715 + ... + 1500110728.

It is an arithmetic number, because the mean of its divisors is an integer number (6000442888).

Almost surely, 2^21001550101 is an apocalyptic number.

It is an amenable number.

21001550101 is a deficient number, since it is larger than the sum of its proper divisors (3000221451).

21001550101 is an equidigital number, since it uses as much as digits as its factorization.

21001550101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000221450.

The product of its (nonzero) digits is 50, while the sum is 16.

The spelling of 21001550101 in words is "twenty-one billion, one million, five hundred fifty thousand, one hundred one".