61390639 has 4 divisors (see below), whose sum is σ = 61406424. Its totient is φ = 61374856.

The previous prime is 61390619. The next prime is 61390649. The reversal of 61390639 is 93609316.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 61390639 - 2¹⁵ = 61357871 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61390598 and 61390607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61390619) 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, 2529 + ... + 11365.

It is an arithmetic number, because the mean of its divisors is an integer number (15351606).

Almost surely, 2^61390639 is an apocalyptic number.

61390639 is a deficient number, since it is larger than the sum of its proper divisors (15785).

61390639 is an equidigital number, since it uses as much as digits as its factorization.

61390639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15784.

The product of its (nonzero) digits is 26244, while the sum is 37.

The square root of 61390639 is about 7835.2178655095. The cubic root of 61390639 is about 394.4882311035.

The spelling of 61390639 in words is "sixty-one million, three hundred ninety thousand, six hundred thirty-nine".