61109323209 has 75 divisors (see below), whose sum is σ = 100859124685. Its totient is φ = 36872799480.

The previous prime is 61109323147. The next prime is 61109323229. The reversal of 61109323209 is 90232390116.

It is a happy number.

The square root of 61109323209 is 247203.

It is a perfect power (a square), and thus also a powerful number.

61109323209 is a `hidden beast` number, since 611 + 0 + 9 + 3 + 2 + 32 + 0 + 9 = 666.

61109323209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61109323209 - 2¹³ = 61109315017 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61109323229) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 269203954 + ... + 269204180.

Almost surely, 2^61109323209 is an apocalyptic number.

61109323209 is the 247203-rd square number.

61109323209 is the 123602-nd centered octagonal number.

It is an amenable number.

61109323209 is a deficient number, since it is larger than the sum of its proper divisors (39749801476).

61109323209 is an frugal number, since it uses more digits than its factorization.

61109323209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

Multiplying 61109323209 by its sum of digits (36), we get a square (2199935635524 = 1483218²).

The spelling of 61109323209 in words is "sixty-one billion, one hundred nine million, three hundred twenty-three thousand, two hundred nine".