61404139 has 4 divisors (see below), whose sum is σ = 61547040. Its totient is φ = 61261240.

The previous prime is 61404131. The next prime is 61404173. The reversal of 61404139 is 93140416.

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 61404139 - 2³ = 61404131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61404131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70804 + ... + 71665.

It is an arithmetic number, because the mean of its divisors is an integer number (15386760).

Almost surely, 2^61404139 is an apocalyptic number.

61404139 is a deficient number, since it is larger than the sum of its proper divisors (142901).

61404139 is a wasteful number, since it uses less digits than its factorization.

61404139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142900.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 61404139 is about 7836.0793130238. The cubic root of 61404139 is about 394.5171453966.

The spelling of 61404139 in words is "sixty-one million, four hundred four thousand, one hundred thirty-nine".