61966420909 has 4 divisors (see below), whose sum is σ = 63135598716. Its totient is φ = 60797243104.

The previous prime is 61966420897. The next prime is 61966420927. The reversal of 61966420909 is 90902466916.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 33469604809 + 28496816100 = 182947^2 + 168810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61966420909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61966426909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 584588824 + ... + 584588929.

It is an arithmetic number, because the mean of its divisors is an integer number (15783899679).

Almost surely, 2^61966420909 is an apocalyptic number.

It is an amenable number.

61966420909 is a deficient number, since it is larger than the sum of its proper divisors (1169177807).

61966420909 is a wasteful number, since it uses less digits than its factorization.

61966420909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169177806.

The product of its (nonzero) digits is 1259712, while the sum is 52.

The spelling of 61966420909 in words is "sixty-one billion, nine hundred sixty-six million, four hundred twenty thousand, nine hundred nine".