61242009 has 4 divisors (see below), whose sum is σ = 81656016. Its totient is φ = 40828004.

The previous prime is 61242001. The next prime is 61242047. The reversal of 61242009 is 90024216.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61242009 - 2³ = 61242001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61242009.

It is not an unprimeable number, because it can be changed into a prime (61242001) 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, 10206999 + ... + 10207004.

It is an arithmetic number, because the mean of its divisors is an integer number (20414004).

Almost surely, 2^61242009 is an apocalyptic number.

It is an amenable number.

61242009 is a deficient number, since it is larger than the sum of its proper divisors (20414007).

61242009 is a wasteful number, since it uses less digits than its factorization.

61242009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20414006.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 61242009 is about 7825.7273783336. The cubic root of 61242009 is about 394.1696148443.

The spelling of 61242009 in words is "sixty-one million, two hundred forty-two thousand, nine".