611913007561 has 2 divisors, whose sum is σ = 611913007562. Its totient is φ = 611913007560.

The previous prime is 611913007547. The next prime is 611913007613. The reversal of 611913007561 is 165700319116.

611913007561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 321897369600 + 290015637961 = 567360^2 + 538531^2 .

It is a cyclic number.

It is not a de Polignac number, because 611913007561 - 2¹⁵ = 611912974793 is a prime.

It is not a weakly prime, because it can be changed into another prime (611913007061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305956503780 + 305956503781.

It is an arithmetic number, because the mean of its divisors is an integer number (305956503781).

Almost surely, 2^611913007561 is an apocalyptic number.

It is an amenable number.

611913007561 is a deficient number, since it is larger than the sum of its proper divisors (1).

611913007561 is an equidigital number, since it uses as much as digits as its factorization.

611913007561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 40.

The spelling of 611913007561 in words is "six hundred eleven billion, nine hundred thirteen million, seven thousand, five hundred sixty-one".