61006099909 has 4 divisors (see below), whose sum is σ = 61007345740. Its totient is φ = 61004854080.

The previous prime is 61006099877. The next prime is 61006099919. The reversal of 61006099909 is 90999060016.

It is a happy number.

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 28265006884 + 32741093025 = 168122^2 + 180945^2 .

It is a cyclic number.

It is not a de Polignac number, because 61006099909 - 2⁵ = 61006099877 is a prime.

It is a super-2 number, since 2×61006099909² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61006099919) 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, 546324 + ... + 648445.

It is an arithmetic number, because the mean of its divisors is an integer number (15251836435).

Almost surely, 2^61006099909 is an apocalyptic number.

It is an amenable number.

61006099909 is a deficient number, since it is larger than the sum of its proper divisors (1245831).

61006099909 is a wasteful number, since it uses less digits than its factorization.

61006099909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245830.

The product of its (nonzero) digits is 236196, while the sum is 49.

The spelling of 61006099909 in words is "sixty-one billion, six million, ninety-nine thousand, nine hundred nine".