61820139 has 4 divisors (see below), whose sum is σ = 82426856. Its totient is φ = 41213424.

The previous prime is 61820119. The next prime is 61820173. The reversal of 61820139 is 93102816.

61820139 is nontrivially palindromic in base 8.

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

It is not a de Polignac number, because 61820139 - 2²¹ = 59722987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61820119) 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, 10303354 + ... + 10303359.

It is an arithmetic number, because the mean of its divisors is an integer number (20606714).

Almost surely, 2^61820139 is an apocalyptic number.

61820139 is a deficient number, since it is larger than the sum of its proper divisors (20606717).

61820139 is a wasteful number, since it uses less digits than its factorization.

61820139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20606716.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 61820139 is about 7862.5783938858. The cubic root of 61820139 is about 395.4060642857.

The spelling of 61820139 in words is "sixty-one million, eight hundred twenty thousand, one hundred thirty-nine".