550100021 has 4 divisors (see below), whose sum is σ = 551658732. Its totient is φ = 548541312.

The previous prime is 550100009. The next prime is 550100029. The reversal of 550100021 is 120001055.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 297735025 + 252364996 = 17255^2 + 15886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-550100021 is a prime.

It is a super-2 number, since 2×550100021² = 605220066208400882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 550099969 and 550100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (550100029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 778826 + ... + 779531.

It is an arithmetic number, because the mean of its divisors is an integer number (137914683).

Almost surely, 2^550100021 is an apocalyptic number.

It is an amenable number.

550100021 is a deficient number, since it is larger than the sum of its proper divisors (1558711).

550100021 is a wasteful number, since it uses less digits than its factorization.

550100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558710.

The product of its (nonzero) digits is 50, while the sum is 14.

The square root of 550100021 is about 23454.2111570609. The cubic root of 550100021 is about 819.3709338525.

Adding to 550100021 its reverse (120001055), we get a palindrome (670101076).

The spelling of 550100021 in words is "five hundred fifty million, one hundred thousand, twenty-one".