551563321 has 4 divisors (see below), whose sum is σ = 553512592. Its totient is φ = 549614052.

The previous prime is 551563307. The next prime is 551563333. The reversal of 551563321 is 123365155.

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, and also an emirpimes, since its reverse is a distinct semiprime: 123365155 = 5 ⋅24673031.

It is a cyclic number.

It is not a de Polignac number, because 551563321 - 2⁵ = 551563289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (551563361) 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, 974211 + ... + 974776.

It is an arithmetic number, because the mean of its divisors is an integer number (138378148).

Almost surely, 2^551563321 is an apocalyptic number.

It is an amenable number.

551563321 is a deficient number, since it is larger than the sum of its proper divisors (1949271).

551563321 is a wasteful number, since it uses less digits than its factorization.

551563321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1949270.

The product of its digits is 13500, while the sum is 31.

The square root of 551563321 is about 23485.3852640318. The cubic root of 551563321 is about 820.0968163497.

The spelling of 551563321 in words is "five hundred fifty-one million, five hundred sixty-three thousand, three hundred twenty-one".