551216881 has 4 divisors (see below), whose sum is σ = 560559600. Its totient is φ = 541874164.

The previous prime is 551216879. The next prime is 551216903. The reversal of 551216881 is 188612155.

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: 188612155 = 5 ⋅37722431.

It is a cyclic number.

It is not a de Polignac number, because 551216881 - 2¹ = 551216879 is a prime.

It is a super-2 number, since 2×551216881² = 607680099798736322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 551216881.

It is not an unprimeable number, because it can be changed into a prime (551216681) 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, 4671271 + ... + 4671388.

It is an arithmetic number, because the mean of its divisors is an integer number (140139900).

Almost surely, 2^551216881 is an apocalyptic number.

It is an amenable number.

551216881 is a deficient number, since it is larger than the sum of its proper divisors (9342719).

551216881 is an equidigital number, since it uses as much as digits as its factorization.

551216881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9342718.

The product of its digits is 19200, while the sum is 37.

The square root of 551216881 is about 23478.0084547220. The cubic root of 551216881 is about 819.9250779257.

The spelling of 551216881 in words is "five hundred fifty-one million, two hundred sixteen thousand, eight hundred eighty-one".