61978539 has 16 divisors (see below), whose sum is σ = 97701120. Its totient is φ = 34194720.

The previous prime is 61978531. The next prime is 61978547. The reversal of 61978539 is 93587916.

It is an interprime number because it is at equal distance from previous prime (61978531) and next prime (61978547).

It is not a de Polignac number, because 61978539 - 2³ = 61978531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61978531) 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 15 ways as a sum of consecutive naturals, for example, 50277 + ... + 51494.

It is an arithmetic number, because the mean of its divisors is an integer number (6106320).

Almost surely, 2^61978539 is an apocalyptic number.

61978539 is a deficient number, since it is larger than the sum of its proper divisors (35722581).

61978539 is a wasteful number, since it uses less digits than its factorization.

61978539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101810.

The product of its digits is 408240, while the sum is 48.

The square root of 61978539 is about 7872.6449811991. The cubic root of 61978539 is about 395.7434888636.

The spelling of 61978539 in words is "sixty-one million, nine hundred seventy-eight thousand, five hundred thirty-nine".