551721051 has 72 divisors (see below), whose sum is σ = 972133344. Its totient is φ = 306529920.

The previous prime is 551721029. The next prime is 551721067. The reversal of 551721051 is 150127155.

551721051 is a `hidden beast` number, since 551 + 7 + 2 + 105 + 1 = 666.

It is not a de Polignac number, because 551721051 - 2¹⁰ = 551720027 is a prime.

It is a super-2 number, since 2×551721051² = 608792236233089202, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (551721091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1882861 + ... + 1883153.

It is an arithmetic number, because the mean of its divisors is an integer number (13501852).

Almost surely, 2^551721051 is an apocalyptic number.

551721051 is a deficient number, since it is larger than the sum of its proper divisors (420412293).

551721051 is an frugal number, since it uses more digits than its factorization.

551721051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 1750, while the sum is 27.

The square root of 551721051 is about 23488.7430698196. The cubic root of 551721051 is about 820.1749829822.

The spelling of 551721051 in words is "five hundred fifty-one million, seven hundred twenty-one thousand, fifty-one".