551910021 has 16 divisors (see below), whose sum is σ = 804318144. Its totient is φ = 334566144.

The previous prime is 551910011. The next prime is 551910053. The reversal of 551910021 is 120019155.

It is not a de Polignac number, because 551910021 - 2⁷ = 551909893 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 551909973 and 551910000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551910011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102996 + ... + 108221.

It is an arithmetic number, because the mean of its divisors is an integer number (50269884).

Almost surely, 2^551910021 is an apocalyptic number.

It is an amenable number.

551910021 is a deficient number, since it is larger than the sum of its proper divisors (252408123).

551910021 is a wasteful number, since it uses less digits than its factorization.

551910021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211300.

The product of its (nonzero) digits is 450, while the sum is 24.

The square root of 551910021 is about 23492.7652906166. The cubic root of 551910021 is about 820.2686116826.

Adding to 551910021 its reverse (120019155), we get a palindrome (671929176).

The spelling of 551910021 in words is "five hundred fifty-one million, nine hundred ten thousand, twenty-one".