561121264 has 40 divisors (see below), whose sum is σ = 1191017520. Its totient is φ = 253977600.

The previous prime is 561121217. The next prime is 561121273. The reversal of 561121264 is 462121165.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 35802 + ... + 49030.

It is an arithmetic number, because the mean of its divisors is an integer number (29775438).

Almost surely, 2^561121264 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561121264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (595508760).

561121264 is an abundant number, since it is smaller than the sum of its proper divisors (629896256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561121264 is a wasteful number, since it uses less digits than its factorization.

561121264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13489 (or 13483 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 561121264 is about 23687.9983113812. The cubic root of 561121264 is about 824.8068180677.

Subtracting from 561121264 its reverse (462121165), we obtain a palindrome (99000099).

The spelling of 561121264 in words is "five hundred sixty-one million, one hundred twenty-one thousand, two hundred sixty-four".