611644261 has 2 divisors, whose sum is σ = 611644262. Its totient is φ = 611644260.

The previous prime is 611644247. The next prime is 611644279. The reversal of 611644261 is 162446116.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540562500 + 71081761 = 23250^2 + 8431^2 .

It is a cyclic number.

It is not a de Polignac number, because 611644261 - 2¹⁹ = 611119973 is a prime.

It is a super-2 number, since 2×611644261² = 748217404028472242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (611644361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305822130 + 305822131.

It is an arithmetic number, because the mean of its divisors is an integer number (305822131).

Almost surely, 2^611644261 is an apocalyptic number.

It is an amenable number.

611644261 is a deficient number, since it is larger than the sum of its proper divisors (1).

611644261 is an equidigital number, since it uses as much as digits as its factorization.

611644261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 31.

The square root of 611644261 is about 24731.4427601788. The cubic root of 611644261 is about 848.8539391899.

The spelling of 611644261 in words is "six hundred eleven million, six hundred forty-four thousand, two hundred sixty-one".