561061551 has 16 divisors (see below), whose sum is σ = 773587584. Its totient is φ = 361499424.

The previous prime is 561061541. The next prime is 561061559. The reversal of 561061551 is 155160165.

It is not a de Polignac number, because 561061551 - 2¹⁰ = 561060527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561061559) 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, 15681 + ... + 36986.

It is an arithmetic number, because the mean of its divisors is an integer number (48349224).

Almost surely, 2^561061551 is an apocalyptic number.

561061551 is a deficient number, since it is larger than the sum of its proper divisors (212526033).

561061551 is a wasteful number, since it uses less digits than its factorization.

561061551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52790.

The product of its (nonzero) digits is 4500, while the sum is 30.

The square root of 561061551 is about 23686.7378716445. The cubic root of 561061551 is about 824.7775591298. Note that the first 3 decimals are identical.

It can be divided in two parts, 5610 and 61551, that added together give a triangular number (67161 = T₃₆₆).

The spelling of 561061551 in words is "five hundred sixty-one million, sixty-one thousand, five hundred fifty-one".