561155501 has 2 divisors, whose sum is σ = 561155502. Its totient is φ = 561155500.

The previous prime is 561155383. The next prime is 561155563. The reversal of 561155501 is 105551165.

It is a happy number.

561155501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560458276 + 697225 = 23674^2 + 835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561155501 is a prime.

It is a super-2 number, since 2×561155501² = 629790992605122002, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561155201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280577750 + 280577751.

It is an arithmetic number, because the mean of its divisors is an integer number (280577751).

Almost surely, 2^561155501 is an apocalyptic number.

It is an amenable number.

561155501 is a deficient number, since it is larger than the sum of its proper divisors (1).

561155501 is an equidigital number, since it uses as much as digits as its factorization.

561155501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 561155501 is about 23688.7209658943. The cubic root of 561155501 is about 824.8235930137.

It can be divided in two parts, 56115 and 5501, that added together give a palindrome (61616).

The spelling of 561155501 in words is "five hundred sixty-one million, one hundred fifty-five thousand, five hundred one".