61503609 has 4 divisors (see below), whose sum is σ = 82004816. Its totient is φ = 41002404.

The previous prime is 61503557. The next prime is 61503641. The reversal of 61503609 is 90630516.

It is a happy number.

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 not a de Polignac number, because 61503609 - 2⁹ = 61503097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61503109) 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, 10250599 + ... + 10250604.

It is an arithmetic number, because the mean of its divisors is an integer number (20501204).

Almost surely, 2^61503609 is an apocalyptic number.

It is an amenable number.

61503609 is a deficient number, since it is larger than the sum of its proper divisors (20501207).

61503609 is a wasteful number, since it uses less digits than its factorization.

61503609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20501206.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 61503609 is about 7842.4236687391. The cubic root of 61503609 is about 394.7300596514.

The spelling of 61503609 in words is "sixty-one million, five hundred three thousand, six hundred nine".