61549139 has 4 divisors (see below), whose sum is σ = 62113920. Its totient is φ = 60984360.

The previous prime is 61549133. The next prime is 61549141. The reversal of 61549139 is 93194516.

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

It is a cyclic number.

It is not a de Polignac number, because 61549139 - 2²⁰ = 60500563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61549133) 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, 282227 + ... + 282444.

It is an arithmetic number, because the mean of its divisors is an integer number (15528480).

Almost surely, 2^61549139 is an apocalyptic number.

61549139 is a deficient number, since it is larger than the sum of its proper divisors (564781).

61549139 is a wasteful number, since it uses less digits than its factorization.

61549139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564780.

The product of its digits is 29160, while the sum is 38.

The square root of 61549139 is about 7845.3259333185. The cubic root of 61549139 is about 394.8274394471.

The spelling of 61549139 in words is "sixty-one million, five hundred forty-nine thousand, one hundred thirty-nine".