551404421 has 4 divisors (see below), whose sum is σ = 561808332. Its totient is φ = 541000512.

The previous prime is 551404417. The next prime is 551404433. The reversal of 551404421 is 124404155.

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 252460321 + 298944100 = 15889^2 + 17290^2 .

It is a cyclic number.

It is not a de Polignac number, because 551404421 - 2² = 551404417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551401421) 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, 5201876 + ... + 5201981.

It is an arithmetic number, because the mean of its divisors is an integer number (140452083).

Almost surely, 2^551404421 is an apocalyptic number.

It is an amenable number.

551404421 is a deficient number, since it is larger than the sum of its proper divisors (10403911).

551404421 is a wasteful number, since it uses less digits than its factorization.

551404421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10403910.

The product of its (nonzero) digits is 3200, while the sum is 26.

The square root of 551404421 is about 23482.0020654117. The cubic root of 551404421 is about 820.0180548275.

Adding to 551404421 its reverse (124404155), we get a palindrome (675808576).

The spelling of 551404421 in words is "five hundred fifty-one million, four hundred four thousand, four hundred twenty-one".