61187639 has 4 divisors (see below), whose sum is σ = 61218360. Its totient is φ = 61156920.

The previous prime is 61187617. The next prime is 61187647. The reversal of 61187639 is 93678116.

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 61187639 - 2¹² = 61183543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61187596 and 61187605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61187039) 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, 12149 + ... + 16430.

It is an arithmetic number, because the mean of its divisors is an integer number (15304590).

Almost surely, 2^61187639 is an apocalyptic number.

61187639 is a deficient number, since it is larger than the sum of its proper divisors (30721).

61187639 is a wasteful number, since it uses less digits than its factorization.

61187639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30720.

The product of its digits is 54432, while the sum is 41.

The square root of 61187639 is about 7822.2528084945. The cubic root of 61187639 is about 394.0529337866.

The spelling of 61187639 in words is "sixty-one million, one hundred eighty-seven thousand, six hundred thirty-nine".